There is a big difference in immerse games ("game that make you feel just like you're there") and realistic games. Graphics don't play much of a role in a realistic game.
I found FEAR 1/2 to be immersive. But they certainly where not realistic. I felt like I was there at parts. But FEAR is a rather generic, mainstream game. Better graphics? Sure. Better music? Yeah. Bullet drop, adjustable sights, no cross hairs, and free aim being standard in FPS games? I doubt it.
I think you're confusing realistic/tactical/simulator games with high tech/immersive games (which can be something like FEAR).
I'll just agree to disagree.
Graphics do play a role in realistic or tactical games. A realistic tactical game with immersive graphics is the game of the future so what exactly are we arguing here anyway? When we talk about a 'realistic' game what we're really talking about is a 'believable' game. In the end, a game is a game, it's only as good as a simulation could ever be. In fact I would rather refer to games these days as experiences. A game can be extremely simple, to say that most gamers are looking for any old game is just not the case. People want an experience out of their game today.
Graphics and realism both serve the same purpose in the end by providing a believable experience, whether or not the content of the game is a simulation of history, what could be, or pure fiction/fantasy. We want realistic weapons handling and authentic loadout/weaponry but we also want realistic particle effects, sounds, muzzle flashes you name it. A 'realistic' tactical simulation must include simulated sensory information, a 3d environment and so on. A nearly pure tactical game (close combat) is not 'realistic' in that it isn't a first person experience, an attempt to simulate the experience of one observer (you). I'm just saying here that the ultimate games of the future will mostly need to simulate that first person observer experience. That takes both believable graphics and details/features.