Update: Less than 24 hours after posting this response, here is what has happened:
Make that -7
-2 "points" or whatever that number is, related to my original question. I cannot work out what occurred or who "voted" to bring that about, where or why—and, frankly, I don't care. It won't prevent me from participating in a positive way with positive people who are likewise enamored with the English language.
What disturbs me is the non-coincidental cowardice / retaliation, and passive-aggressive childishness. Perhaps you folks with the SE chops might want to look into this, though, because this is exactly the behavior in question.
Thank you for speaking up, OP. I was so turned off after being on ELU for only a couple of weeks, that I took a hiatus because of a flurry of horrid responses. The only reason I've returned is because of the email about the new Code of Conduct and the acknowledgement that this is a problem. I will give it another try.
As a newbie and non-programmer type, fwiw, I posted a legitimate and sincere question, only to witness a storm of diva-type frustration and downright rude comments by several on here. I had done my due diligence before posting, by reading and trying to be cognizant of the rules, and posted a simple observation/question on meta where I thought it belonged. I am happy to say that some of the worst things written have been removed, or at least I don't see them anymore. But here is a sample of what remains:
"Respectively, you is wrong. And this is a dup from many sites, including both ELU and MSE."
Thank you for telling me unequivocally that I am wrong. And redundant. The sarcasm is a nice touch.
"...apparently they're nerdy enough to feel strongly prescriptivist in this matter (words' definitions should remain static, and using them in new ways is wrong) instead of descriptivist (definitions change to reflect how people are actually using the word)."
Making assumptions is rarely a good idea. I am neither of the above, but this would have made a good point for respectful discussion—instead of third-party public comment, as if I did not exist.
"Respectfully, "them" is not plural here. It is quite clearly singular. What are you even on about?"
Well, it wasn't at all "quite clearly singular" to me, or I wouldn't have asked. And I was "on about" asking a legitimate question. BTW, inserting "respectfully" does not negate disrespect.
"Even if the OP thinks 'using them in new ways is wrong' they shouldn't have a problem with singular they as it is about as old as singular you!"
Again, making assumptions and putting words in someone else's mouth is rarely wise. I did not know there was a singular "they" or I wouldn't have asked. If everyone knew everything, then we could simply close up shop, don't you think?
"Strange that a self-declared Enlish "ubernerd" would not recognize singular "they."
Completely unnecessary comment. And those who profess to be such "experts" might pay more attention to proofreading before posting.
"Duplicate of meta.stackexchange.com/q/261359 english.stackexchange.com/q/48 QUESTION FORTY EIGHT!"
No need to yell.
I would like to conclude by thanking several users who were polite, stood up for the question, defended my intentions as someone who was simply asking a question, replied with thoughtful points of discussion, and otherwise acted honorably and with the kindness and respect we all must strive to both give and receive.
I am happy to be back, and will know to flag this kind of nonsense in the future. Thank you.