The two things I consider relevant to the discussion are a) the right of people to sell goods to whomever they want to, and b) the injustices that occurr when intolerance is given free reign. I don't think that the latter is sufficient reason to infringe on the former, but I think that you and I and everyone else has a duty to prevent or correct injustices to the extent that we can. I think that this is possible without sliding into self immolation. That may be an irreconcilable difference in our philosophies, but maybe we can find some kind of practical compromise.
For example, I'd like to think that family and charity would prevent old people from dying in the streets if the social security program never existed. In the same way, I hope that family and charity would largely eliminate the suffering caused by the intrusions of bigotry into business.