Why Did The Character Of Otis Driftwood Change So Much Between 1000 Corpses and Rejects?

I think that in the Devils Rejects, you see the real Otis, not the show he puts on when they catch new victims. The familys on the run so Otis and the gang mean business, with the occasional pleasure kill. also I think Rob Zombie wanted a more realistic look and feel to the sequel, 1000 corpses was far more surreal, while Devils Rejects was more down to earth.