Why does reality TV use so many 'train wreck' characters?

Why does reality TV use so many 'train wreck' characters?

Reality television gets a lot of criticism for putting stupid people or crazy people on TV, who you wouldn't normally see on TV. I disagree with that because the funniest sitcoms of the past were the ones about the craziest characters. Even in Seinfeld and Kramer - I mean there's something wrong with that guy, right? But he'd be a great reality show contestant as well. I don't feel like reality television has a monopoly on lunacy or low-brow humor, even. I feel like it crosses all the genres. The only thing that is true of reality television in this respect is that these are real people and it's kind of sad to see that real people are sometimes that stupid or that crazy. The truth is, we see it everyday anyway. The crazy woman at the grocery store or your loony neighbor who is stockpiling weapons - they're just as loony as the people I have on reality television.