I know transphobes don't have a solid grasp of grammar, among many other things, but why would they think that "went" can only be used with singular pronouns? "They went to the store" is correct regardless of whether or not they is singular or plural. A spell checker can't even tell if "they" is being used as a singular pronoun, and it doesn't need to.
"You" was the plural of "thou." Now "you" is both singular and plural, according to context, and "thou" is an archaic form meant to indicate formality (which was done previously by pluralizing "thou" to "you" per the T-V distinction). We also have many new forms to indicate the explicit plural "you" eg. "y'all."
So maybe we use singular "they" but add a new "th'all" for the plural to keep everyone happy.
Here's a fun fact: speaking as a non-native English teacher, I often see that there are some "mistakes" which are much more likely to be made by natives, oddly enough, and they're usually related to spelling the schwa (compatible vs. *compatable, for instance) or to homophones (they're, their, there). Since non-natives don't typically learn by sound and exposure "alone", as a native might, "translating" spoken into written language is often less of an issue, as both are part of the same package in the second language learning process.
That's why you often see non-natives who make zero spelling mistakes but have weird syntax. I've seen countless texts by students who get their they're/their/there right but write unreadable texts. I've also seen texts from native speakers who are very articulate when writing, but there texts show that their having issues with they're spelling.
Having said that, this is just a very stupid individual. This dumbass is using an object pronoun in the subject position. This is something you learn in the first six months of an English course. I've taught this several times, and typically not even non-natives make this mistake. Assuming he's not speaking a very specific dialect that I'm unfamiliar with, I'd say that this is absolutely not the kind of mistake (if you can even call it that) that a native speaker would make, unless they were really overstressing their two neurons in order to make a ridiculously shitty argument. Their are no wrinkles in there brain.
it's really funny how some of the worst people at speaking english are over-wrought bigots set on policing the use of language. no accents or patois i'm aware of use 'them' that way.
As a native speaker, this mistake makes absolutely no sense. It's just absolutely galaxy brain. You have to be trying in order to misunderstand this hard.
Even if this was relevant at all, how do these people think language works? In 2022 if you typed "rizz" it would have had a red line under it. Today it wouldn't because it's apparently a word now.
They're not even good at being pedantic. It should be '"them' is not singular," with single quotes around 'them.' The sentence means to refer to the word itself, not the concept the word points to: Paris is a city in France, but 'Paris' has five letters. Philosophers call it the use/mention distinction; getting it right eliminates a lot of confusion when you're switching between talking about words and talking about concepts.