[CydeWeys]

Good blog post on the subject here: https://motivatedgrammar.wordpress.com/2009/09/10/singular-t...

TL;DR it's been commonly used this way for centuries, all the way back to Shakespeare and even earlier.

There are alternatives, xe/xer/xem, but you can't wish new English words into existence even if they might be useful. You end up sounding sillier trying to use the new made-up words than if you just resign yourself to "they".

And can I add that this comments thread here is peak HN. There's a fascinating article about an interesting part of history I'd never heard of before, and yet all but one of the comments here are nitpicking over word choice. And I'm not helping any either.

[mkr-hn]

I managed to learn Spivak pronouns because I knew someone who used them, but that didn't make it easy.