What is it about rock stars that won't make them quit while they're ahead? ... I mean, just think of some of the more hedonistic behaviour - eating bats (Ozzy Osbourne), the shark episode (Led Zepellin), urinating on the Alamo (Osbourne again) - if any of them behaved like that in a nursing home then they'd be dosed up and diagnosed with senile dementia.
Celebrity management is serious business with serious money involved, which means that there are very serious people involved as well. The entertainment business has its fair share of talented people, managers, assistants and agents who are capable of transforming a talented nobody into a somebody (or keep a talentless somebody in business even).