Maybe you could refresh my memory with an episode or some more details because I don't remember it that way. I remember Adira stating their pronouns, everyone accepting that and using those pronouns and never mentioning it again. I'm pretty damn sure there wasn't some Jordan Peterson type that refused to get with the program.
I'm also pretty sure there wasn't any focus on Stamets' and Culber's "gay" relationship. Their relationship was part of several story elements but the gay aspect was not. Please remind me of any plots involving their relationship that would have to be changed if one of them was a woman.
You are the one making a big deal about these characters because you can't get over their simple existence.
Also, I think it's worth pointing out that Adira was from Earth, which at that point had left the Federation, and had become seemingly a much more paranoid place. So that Adira was uncomfortable and worried about what folks might think of them seems reasonable, since they weren't used to living in the Federation, where being nonbinary isn't something anyone should be worried about sharing with others.