I think the people who idealize the '50s are the people who're of the right race, sexual orientation, and economic status to benefit from what's left of the ills of the '50s, and wish those ills hadn't been diminished. (Seriously, when was the last time you encountered a black person who idealized the '50s?)

Edit: Removed "sex" because there seem to be a few women who idealize the '50s. I've only heard of them secondhand, but my impression is that they really buy into the idea that they're inferior in one way or another and need men to perform tasks that they're incapable of.