As Lanz says, age has nothing to do with it. The argument for ‘realism’ loses a lot of credibility when you refer to aspects of the other approach as ‘Super Mario Brothers monkey jumping sprinting crap’ or label games that take that approach as for ‘kids’. Ditto the claim that fast player movement somehow hurts teamplay potential - this is as simplistic as the argument that Counter Strike has no teamplay, and is often made by players with limited experience of the games they’re arguing against in the first place.
RtCW (and hence W:ET) occupies the middle ground between ‘action’ and ‘realism’. It has relatively limited strafe jumping compared to Quake 3, but the player speed and jumping could be considered excessive by a Call of Duty player. It has machine guns and rifles rather than rocket launchers and nail guns, but these same weapons are considered more ‘arcadey’ than their equivalents in other games. Accuracy is based on movement, but there’s still a crosshair on the screen… and so on. It ends up a reasonably realistic feeling game with some arcadey elements, which some players find distracting, but which make the game what it is for others.
id and SD certainly care and pay a great deal of attention to the kind of realism you get in the current crop of FPS games. Notably, there are no pure ‘action’ games in the top five most played lists on any of the ranking sites (gamespy’s stats pages, csports.net etc).
Realism is important for immersion. If you’re playing a WWII shooter, it’s important that you can’t just run at the enemy at 50mph, firing headshots from the hip with your carbine. Conversely, if you’re playing a game in which you’re an alien cyborg in yellow armour, fighting in a virtual area comprised of narrow ledges with no railings and mysterious floating platforms, it doesn’t matter much that you can jump a metre into the air and fire rockets at your feet to get to a higher ledge. It fits what is already a fairly fantastic game, and doesn’t break immersion. If you could do the same in the trenches in Normandy, you’d start to wonder what the game’s designers had been smoking.
That said, gameplay is more important than immersion, and there are limits to realism - you have to draw the line somewhere. Far Cry multiplayer has a quirky feature where, if you’re low on stamina because you’ve been sprinting, you can’t jump as high. This is realistic, but it’s not a popular feature even with players who enjoy ‘realism’ games. Counter Strike doesn’t give you one life per round because that’s realistic, it does it because it heightens tension and leads to a more exciting game. In the other camp, imagine how dull Tribes would be if you had to walk to the enemy base to grab the flag.
It’s funny how things change - when CS came out, all the Quake players branded it a ‘kids’ game, with its toy weapons and simple player movement…