He has a massive ego... that's why I think he lost his mind... he snapped after people stopped liking his movies... he even tells stories about him getting mad at people for saying they liked some of his movies but not others... he walks away angry.
Trust me, I own his four first movies, all very good in my opinion. Sixth Sense, Unbreakable, Signs, and Village, but after that he lost it. Lady in the Water came out, and most people hated it, then he did happening... then the last airbender... kept getting worse and worse. I've listened to the commentaries of his first four movies... and watched many interviews with him because I was a fan. Everyone knows the guy is into himself, that wasn't even the issue, the issue is when it started effecting his movies. His latest, the last airbender, doesn't even make any sense. the entire movie is just trash. the writing, directing, acting... the sets were kinda cool... but everything else was just garbage. Plus, being a fan of the animated series, he wasn't even trying to be true to the source material. So he has no excuse what so ever for making one of the worst movies I've seen in years.