The problem is if you play enough of parts in films that are sort of more financial products than anything or films in which the girl is a thankless, thoughtless, underwritten character along the way, you're no longer the person who had something fresh or vital to offer. I think it really does start to diminish some part of you, to put yourself through things you don't really want to be doing.
If you're stuck at a piano and you're not a lead guitarist or a lead vocalist, you're kind of at a nine-foot plank and you've got to do something about it.