Partly because it sounds like woke gobbledygook, I suppose. Because it suggests that the simple bedrock concept of gender (as in primarily two, as in male/female) has been imposed by a foreign power to establish political control over a native culture. Which is bullshit, of course.
Thank you, God, for sparing me from the burden of such terminology throughout most of my life. Thank you for that blessing.
At the same time I felt curiously charmed by the “Little Horse” character in Arthur Penn’s Little Big Man (‘70), and I loved Chief Dan George’s “Old Lodge Skins” character (a performance that was Oscar-nominated for Best Supporting Actor) and his “live and let live” approach to life.