He didn't deny service. This is the lie you authoritarians keep using. They were free to come into the store, they were free to buy any product he had. They were not, however, free to force him to make something he has never made and conscript him into their service...which is what you are wanting now.
Let me know where you are confused about the above. Read it, then read it again. Per usual, you let your feelings get in the way and are basing everything on that. No one is arguing that the guys views arent dumb.
I've said before, and it crumbles your entire argument, if things were reversed and someone came in and said make me a cake that says: Gays Burn in Hell, and he refused, you would cheer. Showing there is zero principle behind this, its all feelings based. Not to mention, there is zero evidence he would make that cake either...None.
Again, this is nothing more but the left demanding ultimate compliance or you will be destroyed.