I understand your point and have actually thought through quite carefully which games I let my son see me playing.
MWLL is a very different game experience to Crysis. There's actually very little going on in MWLL which is potentially disturbing for an 8 year old... Large futuristic walking robots and tanks get destroyed, small futuristic robots (BAs) get destroyed, and distant aeros get slightly damaged before flitting back to their runways to repair.
That's very different to Crysis, a game in which most of the enemies are lifelike depictions of modern day people, you often fight up close, and death is rendered in gorey accuracy. I wouldn't let my son see Crysis (or COD, or most other FPSers).
The main parental advisory issues for MWLL are:
1. some of the lewd language that is occasionally encountered on a public server. It's rare, and only sometimes have I needed to pull the plug on a game because someone is doing Mavis Bacon Teaches Profanity in the console. (I searched for a way to disable the text messages actually, but couldn't find one.)
2. the blood spatter effect of a cockpit kill. I think on balance though the effect is fairly "comic book" and therefore not too disturbing.
3. a graphic and gratuitous depiction of a drunk man perpetually pissing himself on top of a mountain. While kids get scat humour, the drunkeness - and in fact, why drunkeness is considered by some to be 'funny' - would be harder to explain. (But in fact the drunk man is easily enough to avoid on that one map).
It could be argued that any kind of game which is about killing anything is inappropriate for a kid. I originally set out to try and shield my kids them from all those things. But when you watch kids TV, and think about what we were all exposed to in terms of violence through Loony Tunes and the like when we were young, and see what happens even in G rated Mario game, you realise that shielding against any depictions of violence is actually impossible and in itself potentially 'cotton wooling'.
So, I focus my parental censorship on games which cross the line into graphic realistic depictions of violence, "gore porn" (ie take delight in the depiction of violent deaths), or most importantly, teach poor moral values by rewarding immoral behavior.
