Well, sometimes, you'll get votes just for being on topic, no matter what the content of the comment is.
Thousands seems out of line for that kind of thing though.
But shit, my highest upvoted post on reddit ever was a one line quip. It was funny, but not that good. I'd make detailed, sourced mini essays and get negative votes.
Lemmy is a bit better about voting up for both topicality and effort to be sure. But we're also all human, so not everyone fact checks everything they come across before voting. They'll often vote based on "truthiness" as much as anything else. I say they, but I catch myself doing it too. I'll run across someone that put good effort in, was on topic, and at least tried to be useful, and that's worth the up vote. Could be wrong as hell, and I'd still think that. But I don't have the inclination to fact check everything. And I don't always have the stamina to respond even when I know there's something off or outright wrong, but I'm not going to down vote unless I suspect they were wrong with ill intent.
So, I think you may have run across something that, while fallacious, is not egregiously so, and/or still nestles into the community's specific bias even if they're aware it's fallacious.
Which, btw, sometimes something can have logical fallacies and not be bad. Doesn't even have to be wrong, though it's like math class where if you did the work wrong, if shouldn't matter if you got the right answer. But on a multiple choice test, you can end up acing a test by accident as long as you're making the same mistakes the right way.
I dunno, forums with voting out vote like functions are weird. As soon as you think you've figured things out, you'll run into things that make no sense again.