They've nailed a woman's breasts to a board on NBC? They've sewn a woman's genitals shut on Fear Factor? Would you be OK with that if they did, on prime time television? Yes or no.
Yes, I get your point. I don't think it's a good thing on Fear Factor, either. It's the same sort of mentality that drove those Bum Fight films. Just because people are stupid enough to consent to hurting themselves does not mean that it's right for other people to pay them to be stupid and hurt themselves.
If you want a real good example, look at VH1's Surviving Nugent. In one episode, he put the contestants in cold mud for hours to see who could endure it. Can you say "hypothermia"? One of the contestants had to go to the hospital. And, yes, I think he should have been charged if she had died.