I think that people cling to gender roles because we depend on binaries. They make everything ostensibly less complicated (although they very obviously don't), because people can place everything into its little black-or-white appointed box, and boom - easy. Gray areas are messy and people don't like messy, because it throws everything we thought we knew about how the world works.
People tend to react to gender variance with this overblown panicky fear, as if the world as we know it is going to end because Angelina Jolie dresses her daughter in boy's clothes or Cher's son got a sex change. I mean, it's a valid fear, but I don't think that we should fear the end of the world as we know it. Because, honestly, the world as we know it is pretty shitty sometimes, and could use a real overhaul in the way things are done.
But as always, that fear symbolizes a much larger, more existential fear. I think people unconsciously think, "What do you mean, girls don't have to wear pink dresses and play with dolls, cook, clean, be second class citizens, etc.? Then what IS a girl, really? and by proxy, If gender isn't something concrete we can depend on, than what in the hell is?"
It's the same damn reason that people tell queer people all the time that they can't be bisexual or whatever because they have to be "one or the other" or tell biracial people that they have to pick "one or the other" identity. People have to be "black or white," "boys or girls," "straight or gay," "republicans or democrats"... Hyperbole, but I make my point.
I really don't think gender necessarily has to be a damaging concept. I think it's unrealistic to say "Just get rid of gender entirely!" because I don't think we have the capacity to just purge gender from our society altogether. Neither would it be productive, because because we're all gonna live our lives in our own gendered capacities and that's totally fine. It's just how to get people's minds out of that linear binary gutter, where it's two endpoints and a scary unknown in between that they fear and despise and use that fear to limit others.
I guess the problem is how to get it from being a linear spectrum to being more like a circle. If that makes any sense. To me, the gender spectrum is a circle, in that it's infinite. A circle can be defined as the curve traced out by a point that moves so that its distance from a given point is constant. At the risk of sounding cheesy, that center point represents being a human, and each individual point on the curve represents that we're all at exactly the same distance from that core. Yes, "Cis" male and "Cis" female are definitely on that circle, but there are infinite points and therefore infinite ways of being a human. It's not a perfect simile (metaphor? Simile? I never could quite get a grasp on those), but it works.
I could also dive deeper into the poststructuralist analysis of gender but that's for another time because it's laaaaate.
