I understand and for the most part agree on a theoretical level. But we can't ignore the very stark differences among people based on gender and sex throughout human history that still apply to the majority of societies today. Language reflects society and words are created to communicate concepts like "outside the norm". I understand that we want the language to preemptively eliminate "the norm" because we're heading toward an eventuality wherein, hopefully, the majority of people will no longer consider people fluxing between two polar gender representations as "different", but that's an idealistic look at a reality that so far doesn't match.
There are a whole lot of people who are scared of what they don't understand, and finding a middle ground to help them with new concepts that threaten to alter everything they've thought they've known their whole lives is, IMO, the best way to promote change. My own views would probably be stuck in a Midwestern Protestant mindset had there not been people doing that for me.