A contestant can quit if they don't want to do something but a lot of them will do it because they're sports. And they know that others have done stuff like this in Bigg Boss tasks. Waxing, Guys wearing sarees and makeup, etc etc. I don't think anything's being done that wasn't done before.
The only suggestion that I thought was truly horrible was asking Deepak to do squats when he had leg injury. But then that was Sreesanth's idea. Hina told him to stop when she saw it was painful.