I think it is because it makes people feel better about themselves....they think my god my family is fucked up....but thank god we're not that fucked up....or something along those lines...
But I agree with you Doug...it is all crap...However, if they brought on gladiator style deathmatches with real blood real gore I may watch it....or if they did a survivor type show where they actually had to survive I would find that entertaining as well...