"Not enough blood, gore, swearing and titties. Dammit, if I'm supposed to shock my parents into pretending to love me, I need my video games to ooze a forced, fake edgy quality not unlike that kid in the black of the classroom who always draws pictures of a horribly mutated Santa Claus."
It wouldn't be so bad if it were only 8-year-old boys bitching about lack of sarcastic quote "hardcore" content, but that's a common complaint amongst adults who were supposed to have passed through the larval stage of being overly impressed by GOOOOOORE ages ago. Yeah, I know you think you're a big man with your screen full of bloodied entrails, but some of us are secure enough in our masculinity that we know how to find joy in the few weird, quirky, somewhat cartoonish games that manage to slip out between the utterly unstimulating brown and grey brick walls of macho games we've complacently come to accept as the norm.
[/rant]
Of course that's only one of many reasons that I have in mind, but it's the one that hasn't been referenced yet. Apart from that, I mostly agree with the above posts.