As far as I'm concerned, if you're paying me I'll play precisely whatever you want me to, with a smile on my face and all the passion I can muster. If you're not paying, I'll play precisely what I want.
I think this may be an attitude I picked up doing orchestral playing up to national youth level- sometimes you just have to smile and get on with it, no matter how much you hate the piece in question, and you have to do it well.