You got a few downvotes, but you’re not wrong. Another issue is if you have tags for everything except being straight, then it sort of implies that being straight is the default “normal” option, and everyone else has to go out of their way to designate themselves as not normal. It’s something that should be left up to the users to choose, instead of having a default.

Sort of like if you had race tags for everything except “white”, it would imply that being white was the expected norm, and everyone else has to mark themselves as outside the norm. Or for a more forced-binary example, what if a game had a “woman” tag, but no other gender tags? It would heavily imply that the expected default is “man”, and every woman (or really anyone who doesn’t explicitly identify as a man) has to self-select.