Destructoid - Why I will support Modern Warfare 2.
Choice is the important word here. Peter Molyneux once interestingly noted that, given a choice, most players decide for themselves not to walk down the path of evil on their first time playing a game. His own game, Fable, allows players to either be good or evil, and evidence suggests that players actually prefer good. While it's a given that there are players out there who will choose to shoot as many civilians as possible for a laugh (and really, I don't think a laugh is a bad thing, even if it is in bad taste), it's totally reasonable to expect that many players will choose to do the 'right' thing.

TechCrunch - Scamville: The Social Gaming Ecosystem Of Hell.
In short, these games try to get people to pay cash for in game currency so they can level up faster and have a better overall experience. Which is fine. But for users who won’t pay cash, a wide variety of “offers” are available where they can get in-game currency in exchange for lead gen-type offers. Most of these offers are bad for consumers because it confusingly gets them to pay far more for in-game currency than if they just paid cash (there are notable exceptions, but the scammy stuff tends to crowd out the legitimate offers). And it’s also bad for legitimate advertisers.