The whole bakery/gay wedding cake thing drives me crazy because so many people equate refusing to decorate a cake in a specific manner with refusing service. Refusing to make a cake with a message that one finds offensive is not the same thing at all as refusing service to someone at a restaurant or retail store or even selling a pre-decorated cake. The defining factor is "work for hire."
- Should a painter who typically paints family portraits be forced to paint a nude couple if he finds painting nudes uncomfortable?
- Should an author who co-authors books be forced to co-author a book on a subject matter she finds offensive (or just uninteresting)?
Any business that's open to the public should serve all members of the public. This means restaurants serve anyone, bakeries sell cakes to anyone who comes into the store, clothing stores sell to anyone selecting an item from the rack. And, in the case of a bakery, if the bakery has an advertised list of pre-defined things they'll put on a cake, they should put any of those things on a cake for anyone who requests it.
Creative and custom work for hire; however, should always be at the discretion of the person performing the work for hire. The scope of the work is immaterial, be it a novel, a painting, or words on a cake.
Refusing to perform creative work that's personally offensive is not at all the same as refusing to transact a retail sale or refusing restaurant service. Equating them misses the point entirely.