I mean to me the whole point of NaN is that it should not equal NaN, so it seems sort of like you are making the complaint in the first sentence in your second sentence, only in a slightly more abstracted way. Unless you are of the opinion there is another better point to NaN?

funny story, I was once interviewing for a job where the tech guy did not know that NaN existed. I guess JavaScript wasn't his language, but not sure what was, and the code was in JavaScript for a Web Dev role.