idiocy. They are just games.
A wholly separate issue is that it would be completely impossible to ban FPS games (just as it would be impossible to ban internet porn), and after a "ban" kids would be playing them just as much.
You could get rid of the console games - but FPS shooters would just move back to PCs, and kids would just be downloading and sharing over the internet even bloodier games written or modded by hackers from Russia, etc.