Realism! Check out the details on this gun. This game doesn't have to be 20 Gb, but if you want guns that look this good, then it does. You'll want a new video card too. Newer than that one. What do you mean I don't even know what card you have? This is a new, realistic game, of course you can't handle it!
It seems to me that when developers talk about realism they aim for visual realism. They make it look like what it is supposed to be. Presumably looking like it is good enough. But if visuals and sound (I forgot sound) are all it takes, then we'd all have PTSD from all those war movies. And from the similarly visually stunning FPS that they keep churning out.
Visuals do not guarantee immersion.
The problem is simulation. What is being simulated? I'm reminded of the 'simulator' we had for driver's ed back in high school. We'd all sit in our little driver's seats with a decent recreation of a steering wheel, gear shift, turn signal, pedals, and other stuff which I'm sure is important (aren't you glad I don't drive much?). It was realistic. The visuals weren't so great, being projected a bit far away on the big screen at the front of the room.
It was a great simulation in all aspects, except two: immersion and choice. Notice how I said the visuals are projected on the screen? Yea, one screen for all of us. We watched a film from a driver's seat and were meant to react to it, but there was almost no feedback. The car went forward whether I braked or floored it. The car turned left regardless of where the wheel was. It didn't even matter if the car was 'on'.
Sound familiar? How about your average FPS? As much as WoW is 'on rails', it is a gloriously free and open-ended sandbox compared to your average FPS. Assault this objective! Do not try to climb over the fence. Except that one fence that is scripted to be climbable. You must climb that one. Is this like war? Well sure, there are times when taking any other path will get you filled with bullets, shrapnel, poison, or dirt which is moving at a high speed relative to your body despite being, from most perspectives, stationary. But can you imagine a soldier that he cannot flank the enemy by hopping a fence or crawling around the back way, that he will instead attack a dozen enemies head-on? And of course he never, ever has backup or the option to retreat. That last one is realistic if we're talking about Soviet soldiers in WWII, but outside of that one specific example, which admittedly covers a lot of territory and numbers, there are some options.
The problem is that immersion requires not just appearance, but also choice.
This may mean a loss of historical accuracy while also being more historically realistic. Washington could have done things differently. He had the choice. He happened to take the choices that led to me being here in the best greatest country ever put here by God, in contrast with other countries which were obviously put here by Satan. But he could have ended up as a Loyalist. He had the choice and if we were to play the American Revolution FPS, we'd better get the chance to betray all we stand for in return for evil British gold.
On a side note, FPS aren't quite as much fun before semi-automatic weapons. I played one based on the Civil War once. It was a bit annoying. You'd shoot and then take approximately ten minutes to reload and shoot again, making it slightly more interactive than a vanilla paladin, but that's another story.
There are narrative limits. I cannot imagine the size of the budget required to write, script, and test the endless possibilities for Mr. Pre-President. We'd need sci-fi-style cloning just to get enough writers. So fine, let's force him to be a traitor. But does he have to freeze his ass off in Valley Forge? Can he pay Benedict Arnold so he doesn't pull a Benedict Arnold?
This may be why I enjoy Civilization so much. It isn't historically accurate, and come to think of it, it isn't historically realistic either, but it's something historical. It captures the possibilities. It shows how decisions matter. The butterfly effects of choices are often amazing to see. The potential for greatness, and evil, is nearly limitless. Because of this, despite what the mechanics or graphics might lack, it achieves a level of realistic immersion.
This semi-sandbox sort of play is a source of replay value. The 'story' is different each time. Maybe one game I find myself in a peaceful world where science and cultures are the 'wars'. At another time, I may see perpetual war, shifting alliances, and half a continent burned down (I still maintain that I had no territorial ambitions, which is why I destroyed it all).
Even when there is an overall developer-created narrative path, sandbox elements can help. Take Stalker for example. Ultimately you will do the final thing, whether it is killing the C-Consciousness or dying horribly in Shadow of Chernobyl or leaving the Zone in Call of Pripyat. Yea, a bit of a strange ending: you leave. No great discoveries or victories, merely escape. But along the way there are choices. You can side with various factions. Traveling you can try to protect fellow Stalkers or leave them to their deaths. Or assist them in dying. Maybe you skip half the missions and beeline for the ending cutscene, a choice which sounds remarkably stupid to me, but which sounds quite a bit like the leveling-skippers of WoW. I actually played through CoP a few times, finding more that I had missed and seeing what choices I could make differently.
Admittedly these are essentially cosmetic choices. The economy in the game is easy enough that a vendor benefit isn't needed. A few weapons are different, but nothing is unavailable, just a little harder to get. But it is enough. I can play as I would if I were actually there. Or, as I would if I were actually there but not hiding in a corner weeping, because let's face it, there is no way I'd be going into a dark cave, alone except for the scary mutants lurking all around.
And yet, as much as I might praise choice and various approaches to realism, sometimes it's nice to take the straightforward route and shoot Nazis in the face.