This is regarding the way people are and how stereotypes are bad. Now, while everyone who plays solitaire on their computer during work can be called a "gamer" I think that the term really is more pointed towards people who put in a significant amount of time into gaming. A gamer is also more apt to go for single player games with an online mode for more replay value- so CoD, Halo, Fable, ME, DA, WoW etc... all big games, and if you play several of them you're a gamer (by my definition).
From what I have seen from the Media, they have determine (for now) that gamers are lonely/depressed, socially awkward/overweight, or easily addicted/stupid. I recently saw a German interview of a kid who plays WoW who chose his character because "He is big and strong, unlike me" (paraphrasing). He pointed to the Dark Portal and said (again paraphrasing) "That may just look like an ordinary portal to you, but to me it is a portal to magical fantasy land where I can be anyone I want to be and make lots of friends and do whatever I want to do." Now, not to offend anyone who does play the game as an escape mechanism- that's perfectly reasonable, but not everyone is like that. Not everyone can't talk to strangers comfortably, are significantly overweight and hide in their parents basement because they failed college. Go to McDonalds and you can see all sorts of people who have been stereotyped as gamers, and for the most part, they're not heavy gamers.
Anyways, I've slightly diverged from the primary topic and want to get back on track. I heard a story four or five years ago about someone who was getting griefed in WoW, somehow tracked down his ganker's IP address, figured out the kids real address, went there and beat the kid up. Yeah, that's incredibly stupid. Yeah, its violent. But at the same time, a woman who was not a gamer locked her child in a closet so that she wouldn't have to worry about him/her or hear him/her. The child died.
From China we often get stories of gamers who go into an internet cafe and play until they die. We get stories of people who killed themselves after their account was hacked. But we also get stories of people who have heart attacks from eating too much- which they could have easily stopped, just as easily as someone can stop playing a game. We have people who kill themselves by accident, because they want the rush of adrenaline.
I think a crowning achievement by mankind recently is the Vancouver Riots. After the Stanley Cup, Boston won, Vancouver lost. The fans of the Bruins went home happily ever after. The losing fans however went wild and wrecked their city. Video Games did not make that crowd violent. They just were. Because they were people, not because of any interests that they may or may not have.
So in the end, stupid people will do stupid things, we can't stop them, and we can't blame any particular interests that they have.