While people have the right of free association, that right needs to be exercised responsibly. Is refusing to work with a man who apposes gay marriage is responsible? How about refusing to work with a Trump supporter, or evangelical Christian?
Things that I think are borderline but should be protected are stuff like religion. This is a tough place for me because I know that because of correlation in ethnicity and religion you can proxy discrimination for race through these so I take the L on the fact that I don't want them protected but I don't have a way to reasonably differentiate them from race-discrimination.
Political affiliation is a protected class in California, and I struggle with this a little. It isn't hard to imagine that there is a world where some race, let's say Centaurians, are generally discriminated against and they have a party: The Equal Rights for Centaurians Party. Discrimination against ERC affiliation is discrimination against Centaurians, just proxied through political affiliation. I don't think that's good for our society.
Any way, my ultimate guide star is free individuals being able to achieve their greatest freedoms without non-consensually intruding on others, so based on how society is organized at any given moment, I think the practice might be to protect political affiliation or to not do so. Ultimately, it may just be the case that sufficient of us decide not to use your product because you're a Trump supporter and then you die. That's life. You can't make me buy your product. That's a much greater sin. Maybe the law constrains your employer to not fire you and so we keep boycotting and you then die and are replaced by a company that doesn't act like you. FWIW, if it were me, it would depend on the situation.
Perhaps that's why it's good for CA to do so, because it is overwhelmingly Democrat-voting. If there were many powerful parties, one could imagine it would be less necessary.
Someone that cannot be promoted to be in charge of other people (that they are most likely bigoted against) or even be trusted to give a fair accounting of who worked hard today and who didn't?
How would it be responsible whatsoever to hire that person to work alongside, much less promote, the diverse cultures that the United States is composed of?
This is a common sentiment, and it's easy to agree with it. But it doesn't really hold up with the idea of a right. If you're "irresponsible"--you exercise your right in a bad way that you shouldn't--should you face consequences? If so, and those consequences prevent you from exercising your right, then you don't really have a right, do you?
Cancel culture and deplatforming just are consequences for "bad" free speech, and the argument against cancel culture is very much "you should tolerate bad speech just because the actual right to freedom of speech is more important than your hurt feelings."