You only have so many productive days in your life. Wasting them being exploited is throwing away money you can never get back. You think actors don't enjoy doing movies? Of course they do, but they expect to be compensated for it. You think sport players hate their sport and only play for the money? Of course not, they just recognize that without them the managers wouldn't be making any money so they demand their part.

Never feel bad about demanding what you are owed.