Also it's been used for centuries by writers who are considered at the top of the craft. It's not a neologism. It dates back to the 14th century. Authors who use "they" as a gender neutral singular pronoun include: Shakespeare, Chaucer, Austen, Dickens, etc.

In fact, it was 18th century schoolteachers who invented the "rule" that it wasn't acceptable usage.

These same losers also invented the "rules" that you can't end a sentence with a preposition, you can't split an infinitive, and you can't start a sentence with a conjunction.

These are all fake rules that were just poorly obfuscated attempts to make English follow Latin grammar (bc Latin was allegedly a "perfect" language)