These people don't generally hear the word "no" as they are surrounded by agents, syncophants and other yes men. The Scientologist's "tithe" is the payment to hear the word "no".
So in ohter words, Hollywood celebs are so used to hearing "yes" all the time, they want to hear "no"? Sounds a bit odd.
BTW, I'm sorry if I was overzealous with the Scientology thing. I kind of like Katie, and I'm not too keen with her joining that organization because I've heard some pretty strange and disturbing things about it.