Some people's most valuable contribution to society is being a warning to others what not to do. Is showing them on TV exploitative? That depends if you think these people should be allowed to make their own decisions or not, even if they are stupid. I think neck/face tattoos are stupid and self-destructive but does that make a tattoo artist that puts one on a willing, adult customer a psychopath?
Prisons are full of stupid people because we still hold them accountable for their own actions despite being stupid. They can't help being stupid either.