I was never a fan of Aaron Carter, but I can give some insight on why his career is likely over. I saw a few clips of the Carter family reality show. As someone has already mentioned, it was horrible. The anger issues and other unflattering things the Carter family displayed for all the world to see, has likely turned off a lot of their fans and would be fans. People in the industry (producers, etc) watch these stars too, and they may feel that it would be better to market some other stars to the public, than to rely on someone who's acting a fool. Trainwreck behavior works for some celebrities and others it doesn't. I believe Aaron Carter is the latter.