Why does Jerry Seinfeld refuse to host the Oscarcast?

It's well known that Jerry Seinfeld has turned down offers to host the Oscar ceremony in the past. But why?

Recently, he blabbed to Britain's Empire magazine, "If I hosted the Oscars and I did it really well, they would just ask me to do it again. And then again. And again. There's no up-side. I don't know, it's just a weird environment. I'm lucky that I can do things that kind of interest me as a challenge, but everybody there is nervous, you know? They want to win their award. They're not there to have fun. I like to go in front of an audience that wants to have fun."