The funny thing is that in terms of actual usage, it's uncontroversial and has been for 600 years. The debate about it is a real-life version of the joke, "I can see it will work in practice, but will it work in theory?"
My favourite real-life example of it's usage is one in which we know that the gender is female, and we know it's singular:
"If a mother wants to use the nursing room, they can just key in the code in their pamphlet".
[1] https://www.reddit.com/r/linguistics/comments/3cgbyv/limitat... gives some good discussion
[2] I can't help but feel that these restrictions are related to nondefinite contexts for "(negative polarity items)[https://en.wikipedia.org/wiki/Polarity_item]", like 'no-one' and 'any', where you can't say e.g.
*I ate any cake
but you can say: I didn't eat any cake
but you can also use it in questions: Did you eat any cake?
This seems related to usages like If someone comes, tell them to wait
vs *If John comes, tell them to wait.It sounds a bit more natural if you say "That user didn't read the article, so they were uninformed."
It does when the gender identity of the subject is known to be neither he nor she!
I'm not a fan. If we have to go somewhere, I'd rather go with 'it'.
The leading clause of the sentence makes it clear that we're talking about an individual but does not indicate their (!) gender. You can use it anywhere that one might also use 'he or she'.
On a similar topic, I find it more amenable in an HN discussion to remove all references to 'you' and 'your'. Its adding nothing to the discussion, can feel like an attack, and distracts from the topic, to the people talking. Its close to Ad Hominem.
But that's because you can choose which set of pronouns you prefer.
(They also have a pretty okay list of genders to choose from, if you're into labeling things)
Because its just as gendered and conflicts with standard usage (which, in English, accepts the use of the masculine linguistic gender for subjects of unknown sex or gender identity, so it is not better from either a "gender neutrality, regardless of accepted usage" standpoint or from a "clarity of communication through conforming to accepted usage" standpoint.)
edit: I'd be interested in understanding why people find this very real scenario to be so downvote worthy. Is it because you find the idea of non-gendered pronouns upsetting, or because you think my example is unrealistic for some reason? Or something else entirely?