I get it, but your wording in the OP missed that nuance. I was merely pointing out that as a society we have decided some reasons to refuse service are unacceptable. It is therefore a lot less inconceivable that other reasons might be considered unacceptable.
For example, I have the right to refuse to serve someone who has written bad checks at my establishment, for example.
Or I have the right to refuse service to someone who has caused harm to my clients.