Because Tyson Chandler and Sam Dalembert are worth 60 Mill (roughly). One bad deal becomes the foundation for another, until one day there's another lockout.
Because of the knee injury, I'd say Nene won't get quite the 60 he wants. Teams will hold the knee over his head. If he really thinks he can get it, he may sign a one year deal, but that wouldn't be to bright to me.