Premise
- There is an English language construct called singular they
- SE writers would like to do their best to use the correct way to address readers.
- SE readers might prefer pronouns that are not obvious or use singular they.
If you don't agree with or want to discuss this premise, I don't think there is a shortage of questions right now that you can take part in to do so. Just click the back button in your browser and I'm sure there will be one on the front page that you can add to. This one is to discuss English levels, not why or how pronouns should or should not be used.
Anecdote
My native language is not English. I have a college level education from a leading industry nation. That includes 7 years of mandatory English in school and two more years of mandatory English in my professional education. Add a nerdy interest in English books and computer games and a professional programmer career on top and you have a lot of English, both formal education and just plain everyday usage.
And yet... I was introduced to "singular they" right here on a site of the SE network, when I saw an edit of a post I had written and I was furious... some idiot had totally misunderstood me and had switched all the pronouns to plural. And now it was all wrong! I was 1 second away from clicking "revert to previous" when I though: wait, that is a 100K user, they won't just edit 20 pronouns in my post without reading and double checking. So, did I get something wrong? Well, turns out there is something called "singular they" I had just never heard of it before, in 9 years of English as a foreign language classes and another 15 years of using it after that.
Data
Singular they is not taught in EFL classes or textbooks. At least not officially. Obviously teachers may take their own little breaks from the books and focus on what they think is important, but it's not in the curriculum. The best source I could find were interviews with EFL textbook publishers that told the media it would take years to get that into the books. Assuming people need to read those books afterwards and learn English according to those lessons, we are talking about a decade from now for singular they to become part of the default education.
Current State of Affairs
The current level of proficiency required on SE sites is next to zero. I remember that I proposed that questions must contain a question mark, so we can filter out completely unclear question before they get posted. The reply basically was "How dare you assume that level of English proficiency! We must be inclusive of all the people out there that don't have that level of understanding". I'm pretty sure that questions marks are covered in the very first official basic textbooks.
Discussion
So how do we reconcile those two? How do we allow people of all levels of English proficiency and at the same time make those happy that request a certain level of respect that can only be reached through an education level above normal English as a foreign language?