Lords of Salem was him doing a Polanski movie, it was more along the lines of Repulsion and The Tenant than anything else.
I think people get turned off by his movies because they're all collections of things Rob Zombie likes. So it's all swearing, violence, Halloween, B-movies, etc etc. He doesn't make any effort to disguise that he's really making these movies for himself. He's almost like Tarantino (not in terms of quality).