Responding late so this may have been stated already, but why not just bake the damned cake? If they are activists (as all of these cases are - they probably shopped around until they found a bakery that would not bake it) then they would not buy there and move on to the next bakery that they think won't bake it for them so they can make their point and win their lawsuit. Otherwise, for the owner, state clearly in your ads or promos that you will not bake cakes for gays, muslims, jews, christians, zoroastrians, or whatever, and let the market make its choice? IF that is against the law, so beit, and take your chances.
We're stupid. We should be going to muslim bakeries and ordering bar mitzvah cakes, or 'God Bless Jesus' cakes, then using the same tactic. If they chose to bake them, I wouldn't eat them, but just saying.
Just a follow up. These cases are non-sequiturs but help the left advance their agenda. How many of you that own businesses ask your customers what their sexual orientation or religious affiliation is before deciding if you will take their business? Seriously, I would love to hear responses from business owners who apply that standard.