I don't watch Smackdown at all anymore and I am a "hardcore" fan.
The big problem isn't the stars, SD does have Eddie, RVD, Booker, Taker, Rey, Cena, hell even the Dudley Boyz. SD sucks because the storylines sucks. Raw is a lot better right now because of the storylines more so than the stars.
I'd much rather watch a wrestling show that has good storylines than established stars. ECW was hot during 95 and 96 because they had interesting/good storylines, not so much established stars.