So, when, say, bouncer not letting you inside a club, because he didn't like the way you look it feels bad, but people manage to deal with that. But it's not ok to refuse service when it comes to homophobic bakers and florists. Why?
My guess would be that when it comes to food people feel totally different about discrimination.
Just try to feel following situations:
Phrase "I'm not letting you in coz you should dress better" feels offencive, sad and just wrong.
But phrase "I'm not giving you that cake coz your dress is ugly!" sounds so inhumane and facist.