Sure it does. Notice i said unreasonable harm. There is a clear distinction between refusing to take someone's wedding photo and providing someone with life saving care.

There are US Court cases that deal with this distinction.

Edit: i originally said unnecessarily as opposed to unreasonably... But the point still stands

But I mean if you don’t force people to serve the entire public you risk some presumably unwanted consequences. Should a whole grocery chain be able to say no blacks? What if it’s the only one in the town? Should realtors be allowed to refuse to sell houses to non whites? What if that means all the black people get forced into one part of town, and coincidentally that part has shitty services and other unwanted traits?

Those are examples of public, structural discrimination, which imo is the kind of discrimination that is manageable with laws pretty well. However there is also the kind of individual, private discrimination that can not really be solved by the law. I think it absolutely should be illegal for a company to openly discriminate a group, let's say by putting up a "No XY" sign and officially not serving XY. However, I also see the limits of how much such laws can do in practice. For example despite such a law being in place, a company could easily still not serve XY -just inofficially- and simply claim a full schedule whenever XY people show up/call, without the law being able to do anything about it. That is why I think laws are not enough and in the end a real social change is necessary to end these types of unjust discrimination.

Is the rule “as long as there’s alternatives it’s ok”? Separate but equal was already decided to be unequal.

Discrimination based on inherent traits is unjust af and therefore can never be "okay".

On the other hand, I do want to be able to refuse service to Nazis.

I feel the same

Maybe the key is naziism is wholly something you choose. But I also don’t want people to be able to refuse service to, like, union members.

It's not a simple topic, right? On one hand, I would want it to be legal to put up a "we don serve Nazis" sign, on the other hand, one could argue that someone who was born into a Nazi family and was constantly spoon fed the ideology from the beginning, never really had a chance to not become a Nazi.

There’s no universal “anti social behavior” metric, unfortunately, I don’t think.

In the end I think only education that leads to the understanding that people who are different from you are not your enemies, can help the problem.