Given how the talent level has gone down the toilet, I would say that the 6 figure contract no longer has any appeal to any serious talent. Half these guys don't even fight in their right weight class, most of the winners and runners up from recent TUFs just end up moving down a weight class. They don't even care enough to audition for their actual weight class, because they know they can still probably win at a higher weight class because the talent level is so low.
It's just not enough money anymore. If I'm a guy who is a few wins away from being in the UFC, I'm not going to audition for TUF and then fight 3 times (preliminary bout to get into the house, first round, quarter finals and semi finals) for free. There's money elsewhere in MMA now, maybe not UFC money, but still much better than fighting for free.
I thought FOX would understand that the UFC fanbase has evolved from these "just bleed" assholes to guys who want to watch a legitimate competition, but they still put these guys in that are seriously not good fighters but appeal to those "just bleed" fans. It's embarrassing to know that casual UFC fans watch the show and think Justin Lane is an example of a typical MMA fighter.
Either they have to revamp the show with legit prize money to get real fighters on the show, or just scrap it all together. I see what they're doing with making Sonnen and Jones coaches, but at the end of the day it's all about the fighters actually competing.