The Donut said:The main reason for not having body parts that come apart from each other is the ESRB rating. If they have such graphical violence be it bloody or not, they'd have to raise the rating of the game.
Theres plenty of games with decapitation and gore well beyond the realms of BF2 or even HL2 and Doom3. ESRB rated M games is going to get M as long as theres no sex.
Last games i knew of coming out with full body dismemberment was FEAR and DNF. But there have been plenty out within the last year or two that simply allow you to decapitate and do other horrible things.
Look at Postal 2. I think another was, Devistation.
Realistic games take up a very small and elite market. Last one i played that was any good was Hidden and Dangerous 2 on the hardest difficulty setting. AI could of been smarter but if you got cought, you were pretty much dead.