It's much cheaper to make games that are fantasy and anything goes.
Games like COD4, BF, etc, you have to model real-world objects, hire military consultants, get licensing for props in-game due to weapons and gear design.
If you can bang out the same crap each year, incrementally making it more "beast" for the 14 year olds, (CYBERZOMBIES!) and still make record sales each year, then what's the incentive to listen to the minority of players that want a more realistic experience?
COD4 remastered is not an example of listening to people, it's an extra way to make money re-releasing a game that has already made it's profits, no new licensing fees required. It entices older, more nostalgic players to buy a game they otherwise would not have if it wasn't for the chance to play one of the last great CODs with friends again.