Indeed,
evangelical leaders were at the forefront of the abolition movement, and very much overall show a special love for Jews, and defend Israel, while it is liberals who have been the ones harassing and even physically attacking conservatives in restaurants, etc., and work to exclude them from the marketplace. And as here, to demonize those who refuse to be complicit in celebrating immorality, as if they were KKK members.
But the case at issue here is not that a business saying “no Jews served here,” but that of refusing to contract to create a work for the expressed purpose of celebrating an event that was against the law of God - as were other events the baker also refused service for - as well as (at the time) being contrary to the highest law of the state.
Straights would also be denied contracting to create a work for the purpose of celebrating a homosexual wedding, or that btwn man and animal, or divorce, while homosexuals could contract for a birthday or graduation cake, etc., or possibly a cake for their wedding or anniversary if one had asked, and not said it was for a homosexual wedding, the nature of which being the issue.
Thus rather than denying a class of people any service (as per your analogy) or the same freedom others have, no class of people could contract for the celebration of any clearly immoral purpose.
Rather than this being analogous to your “no Jews served here" analogy, as regards Jews it is akin to that of a Jewish (or Muslim market) that supplies animal meat denying a request for ham, which lovers of swine flesh could say was discrimination, though as in the Masterpiece case, a number of other businesses would supply what was requested.
But can a bakery state it considers homosexual wedding to be morally no-kosher and thus refuse to facilitate celebrating them?
What you can argue is that this denial would be akin to a business refusing to create a work for anyone for the expressed purpose of the celebration of a racially mixed marriage, just as the business refused to create other works for celebrations it considered immoral.
Homosexual unions are not a matter of race, yet affirming this as a religious right could lead to allowing a Muslim bakery refusing to agree to create a work for anyone for the expressed purpose of the celebration of a Jewish bar mizpeh.
Courts would most likely uphold the right of a commercial painter to choose what he will paint, and refuse to create images he considers phonographic, but lovers of such are not provided the rights as a class that race, and now sexual orientation and behavior have. Thus as said, it is the latter that is the problem, making race, which is amoral, equal to a sexual attraction (even if fluid) and behavior.