I registered an account here specifically to reply to this discussion.
In MW I play an assassin type character, and although I agree the games as of late are cutting down on one ability to roleplay, I feel that it is precisely that potential to imagine and truly make the game experience personal that is one of the most important things that can be included in any rpg.
I use a crossbow and a dagger or shortsword, not because they deal out the damage uberqwik, but because that is the 'realistic' choice for an assassin's weapons. Sure, I tend to die a lot, but that forces me to play the assassin as it was meant to be played: in the shadows. If they were to take out sneaking because it wasn't a popular choice with gamers, myself and many people like me (the snipers/campers of Quake and other fps) (btw, I'm not a camper) would not be very satisfied. Furthermore, it takes out the potential for enemies to use those unincluded elements. No realistic enemy thieves, as in BG2. No enemy ambushes using any tactics other than "rush pc with orc barbarians". Talking generally here, which is more plausable; a squad of dwarven archers, or a squad of dwarven crossbowmen? A company of halfling archers or a company of halfling slingers? When you take away 'small, unused, unwanted' elements like crossbows and slings, you risk taking away an atmosphere of immersion. Even if crossbows and slings were crappy and my pc never used them for that reason, I would expect to see dwarves using crossbows (or cannons...) and halflings using slings.
Granted, those things weren't in MW, but when you take the potential for them out, you go into the game feeling...differently. Personally, when I saw the character development process for MW, I was thinking "How are these skills going to be used against me? What weapons will I come up against?" When I was a noob to MW, I thought crossbows were going to be the daddy of ranged combat. Even though they arent, it kept me alert and vigilent until I found this forum. Thanks for ruining things for me...(sniff)...(sob)...
Just my two cents...