A simple grammar primer:
Unless we always call ourselves by our names, we use pronouns as a subsititute. When someone is speaking about me (me is a pronoun), they (pronoun) can say “she” (pronoun). Pronouns replace names. It’s as simple as that. Pronouns are shorthand. In English, as in a variety of languages, we use gendered pronouns when talking about individuals. Groups are generic; English has that advantage over, say, French, which also genders groups of people and things.
I’m neither a grammarian nor a linguist. I have not studied the history of gendered pronouns, so I cannot share a clever history about how they evolved. But I can say I’ve never been a fan. Adding gender to a pronoun or, for that matter, to names has seemed unnecessary. Tables are feminine? Why? Perhaps my disdain comes from all the noun declensions I had to do as a kid. Or maybe it is because I saw boys getting away with more fun and that association stuck. Either way, there was too much distinction and not enough focus on people as people. Or tables as tables.
Here we are, working as best we can with the language we have—language that is forever morphing (6 7, anyone?). We have pronouns that stand in for our names—names we often change on our own. I know many people who use a middle name instead of their given name. Some even use a short form. Maybe they go by another name all together. I’d dare say even children choose how they want to be called. So why they cannot choose their own pronouns without adults fluttering about absolutely baffles me. If a child knows who they are, they can name themselves.
And the trouble with sticking opinions or laws into other people’s fundamentally personal decision to name themselves the way they choose is that we end up taking away their agency. Eroding someone’s sense of self is a dangerous game, and there are adults playing with loaded pistols. There’s nothing funny about it.