There are certainly a number of musicians out there that are as demanding of outstanding work, and as tough on their band members. (Immediate examples include the late great Frank Zappa, as well as David Bowie) When a guitarist or drummer is asked to session for someone like this, overall, it means said musician has 'arrived'. The career has nowhere to go but up...

Why does it seem like nearly everyone and andyone that has played with Prince has tanked afterwards?

Among the many folks that I can think of offhand that I've loved in Prince's band, I can't think of anyone that still has a STRONG career after their years with the Man.

Is it respect, the music community, some personality issue, or something else entirely?

Queenyl