Oh Geraldine, would that the Founding Fathers had conceived of such a group as "business owners" and understood their need for protection!

Civil rights protect IMMUTABLE characteristics. Choosing to become a business owner is the choice to accept public accommodation. You can't choose to be black. You can't choose to be female. But you have all the choice in the world whether you wish to engage in the grubbiness of public commerce. 

(What an insult to those who have suffered -- even died -- for the right to worship according to their own conscience to sully their memory with some cockamamie insistence that worshiping Mammon is worshiping God! Blasphemy.)

BTW - there is no "gay wedding cake" anything. There's just a wedding cake. Mr. Phillips has a right to withhold "expressive intent" (that's inherently a very narrow matter) but he cannot just refuse to sell wedding cakes to whole classes of people.