Its the advanced age (and general wizenedness) which I want to focus on. All three are immensely powerful beings, venerated across the lands and respected as such. There is the implication that their immeasurable power was gained through many years of learning, training and reading dusty scrolls on the arcane arts. So much time and effort has to go into developing their skill that they presumably forget to shave for a couple of decades, leading to impressive beards. Similarly, with time being of the essence, they don't want to waste precious seconds unbuttoning or unzipping flies, so they all go for cloaks and cowls which allow just a quick lift and you're ready to roll. My point is that their training consumes decades of their lives, and by the time they reach the kind of power where they might legitimately call themselves wizards they at least appear to be very old men.
So where on earth is this trusted archetype in modern gaming? The Guild Wars elementalist, the Warcraft Mage, the Diablo Wizard, Amadeus in Trine, the wizards in Magicka... all fresh faced youths in the prime of their lives. Have they even had half the time to develop skills through which they might call themselves spellcasters of note? I say nay. Some games (like Skyrim) give you the option to change the appearance of age of your character, but this is for appearances sake only - to all other agents in the game you will still be a youth of relative inexperience.
In fact, the old wizard archetype is often employed as a secondary character to your own: the greybeards in Skyrim being a good example. Again, they are elderly bearded advisers - though their wisdom could be somewhat questioned. But still I miss the chance to play that character - a character whose staff is not only a deadly weapon, but also an essential walking stick to soothe his aching back! In the future I want my RPGs to include in character creation a slider for "hunchbackedness" and the further I slide it to the left, the more broken and bent my character becomes. Instead of dodge rolling, he could shift or phase out of the way, instead of fizzing out puns like no tomorrow, he can dispense golden nuggets of wisdom ("a wizard arrives precisely when he means to!").
Power does not necessarily need to be communicated through vim and vigour, the kind of boundless energy which the Guild Wars elementalist seems to possess in spades - shooting around, throwing out wise-cracks and one liners like no tomorrow. Power can be like Yoda - old and immense, but with the appearance of being small and inert. These old characters, Merlin, Gandalf, Dumbledore were thoughtful in their movements, slow and steady, their calm masking their immeasurable power because when required to act they act swiftly and decisively, I understand that there are certain examples (I believe the wizard character in Gauntlet is old and beardy) but rarely are we given the chance to factor age into a game which allows character customisation and certainly in MMOs the robe-wearing bearded wizard seems to have been superseded by the young spell-slinger type.
I get that game developers want us to identify with the characters we create, and its easier for us to identify with a character who appears to be of a similar age to the standard gaming demographic. Perhaps I'm getting a little more advanced in age now and with my back I can't see myself dodge rolling much in the near future. Instead, I'd rather play a character who is as immobile as I am, but still gives me the feeling of being old and powerful.
There is a whole other article about how wizards are venerated, but witches (until the Harry Potter franchise at least) got the shorter end of the stick and largely still do. That's a topic for another time and one I'm sure which is tied up with various cultural views on power and femininity.