As someone who is nonbinary, I don't care if someone comes to me telling me that. Like... You can believe there are only 2 genders. You can still believe that and still be respectful. That's what my friend does. She believes there are two genders but she still respects the fact that I use they/them. I just don't see why everyone is so upset just because somebody want to identify as something else. So what? It's not effecting you in any way. While yes, they are speaking the truth. There's a lot of straight people who are also just as guilty.