I could be wrong but it seems you have issues with the idea of games for adults and games for kids. The fact that a game is unsuitable for your child to play, or even watch you play, prevents you from enjoying certain games seems just wrong. Did you stop watching movies rated PG-13 or higher as well?
And why is it wrong for young children to understand the concept of life and death? I mean, an overly gory game is one thing but I don't think my ten year old slaughtering opponents by the dozens in Minecraft is going to cause her to grow up with psychopathic urges.