Probably it was both. I would go so far as to say definitely.
You brought this on yourselves, but it didn't have to be that way. Not at all.
Journey with me to the past...to 1974 and "where it all began" and see why a wizard should certainly be allowed to hold his own in a melee.
The first game, Dungeons and Dragons, was born from tabletop wargaming, which is very abstract in its idea of combat. While the figures are moved and put into combat routines, they are static, thus the swing of the sword, the clash against the shield, the flight of the arrows is not seen but is understood. When that tabletop wargame added fantasy rules wizards entered the field of battle in the manner of their literary forebears, legendary spell casters such as Gandalf and Merlin. We all know that Gandalf swung a sword with the best of them and fought in bloody melees, so why not also the wizards of Chainmail. In this abstract combat world it mattered little if the wizard was swinging a staff or blasting away with an eldritch bolt, you rolled your dice, consulted the matrix and that orc went down screaming.
When the shift was made to RPG and D&D was born the mighty units of the Chainmail army were modified and given a scaling level system to allow for development and improvement through play. No longer was a wizard a unit with a selection of spells to cast at will for the duration of a single battle. Now the wizard, and his companions the fighter, the cleric and eventually the thief, had to contend with long term, indefinite adventures and dungeon delves that might last days in game world time. A new rule was created restricting the number of spells the wizard had available to him based on levels and days. Further it had to be clearly determined what sort of weapons he could carry and how well he could fight. Using the combat matrix from Chainmail the wizard fought as a man but at 2nd level he fought as a man+1. Thus a neophyte wizard was as good as any normal man and soon better and eventually much, much better. He'd never be a superhero level combatant like his stout fighter companions but he would have magic to compensate for that.
Not that I think you are unable to grasp this but for comparison the fighter started at man+1, which means that he was a cut above a normal man in terms of his combat. The +1 in D&D equals 5%, so with man+1 combat and 1D6+1 hit dice it is like saying that a neophyte hero is 105% of a normal man.
Now for weapons our wizard could use only a dagger, but that was okay because originally all weapons did the same damage. I've said it before but it must be repeated here: 1 spell per day at first level!
With only 1 spell at his disposal and the ability to fight as well as any unarmored man the wizard was obviously not only expected to engage in melee, he had a solid chance of surviving and killing his foes.
Then shit changed. Over the intervening years the wizard saw his hit dice drop and everyone else's get better. He saw a change in weapon damage such that daggers and staves, his only options, were pitiful in their damage output and all the monsters got tougher too.
By the 2nd edition of AD&D the poor neophyte 1st level mage had 1D4 hit points, 1 weapon choice (dagger, staff, sling, dart) and of course, 1 spell per day at first level!
By comparison a normal person (0 level human) had 1D8 hit points, could use a sword, could wear some armor and had the same base chance to hit as any 1st level "hero" (20 on a 1d20 or 5%). So effectively an apprentice wizard would get his ass kicked by a farmer, a blacksmith, a tax collector, a bar maid, your grandmother...the list is endless. With only 1 spell available to him, and with the only damage spell doing, at best 5 points of damage, the wizard had no choice but to engage in melee combat, yet his survival was not likely. This leads to players standing way in the back in conflicts and throwing the weapon known as a dart (think yard darts, not pub darts). Sure, if he happened to find a wand or something he could certainly attack that way, but we are looking at base chances here, not the Monty Haul DM output.
Fast forward to the MMORPG era. As RPGs developed popularity many options existed outside of the original game, such as GURPS, Vampire the Masquerade, MERPS, and too many for me to list here. Each game varied in content and concept, but fantasy genre seemed to be the most prevalent and each fantasy genre game determined its own wizard rules. You had spell point games where a wizard could cast as many times as he had points to power his spells, you had generic games where the player could build his character any way he liked with no class restrictions and thus you could have a melee combat savvy and survivable wizard, and you had games that were solely focused on magic users and thus ran the gamut of wizard possibilities. It seemed that there was a surfeit of developers and players who could see a wizard in melee. There were also plenty of games with opportunities for a wizard to never enter melee. Yet for all of this the venerable grandfather of RPG, D&D, was still forcing the wizard into melee through lack of spells and simultaneously handicapping the mage's any chance of survival in said melee, much less success. The MMORPG had to deal with a very different problem. The old spell points and 1 spell per day simply did not work in the MMO environment which was persistent. Monsters had to "respawn" to give all players an environmental challenge. Options were limited by programming and UI space. As a result players needed, and indeed expected, to be able to cast spells at will. Developers responded in differing ways including regenerating spell points and minor attack spells that required no power at all. The gamer mindset is hard to fathom at times. The wizard players expected something called "balance". In essence they wanted their spells to be the equal of the warriors' swords and the warriors wanted their swords to be the equal of wizards' spells.
The traditional balance of the tabletop had been that the wizard started in a weak position and ended strong while warriors started strong and advanced by small degrees to end strong. To illustrate look at Magic Missile, a spell that does 1d4+1 points of damage. You know, once per day. A long sword does 1d8 points of damage, all day, as much as you swing it. When the wizard reaches 5th level and can finally cast the suspiciously famous "Fireball" it will do 5d6 points of damage (and increase each level until it caps at 10d6) but the long sword will still be doing only 1d8 points of damage. Mind you, the warrior can probably hit more often now, including multiple attacks in a round but the classic Fireball is an area of effect attack with massive damage and at 5th level 1 TIME PER DAY. At 20th level the warrior has tons of hit points and magic swords and can attack multiple times a round and the wizard? The wizard can send you away to some dark dimension from which there is no escaping in a puff of smoke. There's your balance.
That doesn't work for MMOs. As a result the development led to wizards having scaling fireballs, essentially. A tiny little flare at 1st level that does damage comparable to the warrior's sword. Then as he leveled the fireball leveled with him. Well that's not fair to warriors so the warrior gets access to long swords that increase in damage as well. Can the wizard melee? Depends on the game, but if he can he is quickly killed due to the logic of the balance. His stick just doesn't hurt anything, he has no armor and no hit points. Down he goes should any monster or PVP player get within stabby range. The trade off for throwing fire at things is apparently that the things are all made of asbestos.
It's not right. Dammit IT IS NOT RIGHT! For all of its flaws the venerable DnD at least once understood the nature of the wizard. It's FANTASY not REALITY. It's GANDALF, DAMMIT!
Melee is the default combat. You don't need a room of 1001 orcs either. Make the combats meaningful each time instead of throwing monster after monster at the party. Yes, I am suggesting quality over quantity. This is nigh impossible in an MMO due to the nature of the persistent shared world. Instanced play solves this problem to some degree. What can't be solved is the problem of player perception. Wizard shoots fireballs. Warrior hits with sword. That's the way it has to be. None of this would be a problem if wizards stood a snowball's chance in Hell in a melee, but they just don't for the most part. They wouldn't have to do if the original rules had not handicapped their spells, but then the original rules were written by dudes that understood the essence of magic. Magic is mysterious, complex and miraculous. Magic is not for nuking but for opening the rune-locked door. Magic if for lighting the way deep underground when even torches cannot pierce the darkness. Magic is a wonderful tool not a laser gun. Dare I say it? Magic is convincing Stormtroopers that these are not the droids they are looking for to avoid melee.
As it stands today I have a wizard in Neverwinter that fights with a ball. A ball floating beside his head. He has 0 melee. None. Zip. Zilch. He just runs around shooting magic missiles and casting the same 4 spells constantly. I find this offensive and unfulfilling, but then most MMO wizards are to me.
Now if your logic is working you might say, "But, Punk, the original wizard had to engage in melee because he only had a precious handful of spells per day. If he was able to cast spells all the time as his 'weapon' he would certainly have done so. Thus your complaint is unfounded."
I thought of that. I promise that I did. I could accept that save that it destroys the essential magicness of magic. If magic is just another raygun then it lacks that essential magical quality. No, I'm afraid you have to go back to tabletop for that experience and you have to go back far enough that the wizard stands a reasonable chance of melee survival. You have to stop thinking of the wizard as a wussy in a dress that serves a "role" in the party and start thinking of him as a person that controls fundamental forces beyond the ken of normal men, but is still, for all that, a mortal man. This distorted notion of balance is the problem and it can't be fixed in an MMO, I'm afraid.
Yeah, I realize this is just griping on my part, but this crap bugs me.