I disagree with your appraisal but as an example that splits your uprights: let's say the photographer in question is a member of a demographic that is or was persecuted in some way and those trying to hire them are members of the persecuting demographic.

A Ukrainian photographer being asked to cover a family event for a family of Russians. Even if nobody involved has anything to do with the war, the situation could very likely make the photographer uncomfortable, and I don't think that most people would fault the photographer for passing on the opportunity.

A black photographer being asked to cover a wedding being held on the grounds of a former Southern plantation is another case where I feel that the photographer would be understandably uncomfortable and the photographer would be completely justified in declining.

Even something like, say, an artist who is the daughter of Filipino parents who were subjected to horrific treatment during the japanese occupation during ww2, and now she's being approached by a Japanese patron to commission her for a piece. While there's a good chance that the artist may not be affected by her family's history and be able to create the commission without any issue, I also feel that if that's not the case, and the dynamic makes her uncomfortable, she would be completely within her rights to simply decline.

There's even the possibility of the effects of real trauma being unjustly applied: the black photographer who was assaulted by a white person and now simply doesn't want to work events for white people (or vice versa). The female SA victim who won't work with men.

Simply flipping the party who has a condition they can't change seems (to me at least) to change the dynamic. Having non-choice conditions on both sides changes the dynamic even more.

As such, I feel that the only fair situation is one in which the business contact is understood to be a two party contract, with both sides having full agency over their decision about whether to enter into the agreement for any reason. It's different when it's like a shop owner or something, where the entire transaction takes a minute and the goods and services they provide are open to the public in general.

But in the cases I'm talking about, I see the business models and getting comparable to valves or switches in a system. Some valves are "always open" except in specific circumstances: the main water valve, the valve from the pipes into your toilet tank, etc. and they're just left open outside of specific special circumstances. Others are "always closed" outside of special circumstances: the bypass for a filter, or a drainage valve, or even the knobs on the sink which are only open when you're actually using it. I see storefronts as "always open" valves, providing their services to the public in general unless they're closed. In contrast, contract workers are "always closed" valves, not working by default, and their valve of work only opens when they agree to it. And in that business model, they should be free to keep that valve closed for any reason, regardless of whether it's a good or shitty reason to anyone else.

While you or I may not particularly like or approve of one party or the other's reasoning for opting out of a contract, I do believe it should be their decision.