I will note that people make arguments via questions pretty often in normal conversation, so that's not necessarily an accusation of significant bad faith. It could be more of a complaint about rhetorical technique.

But let's treat it as an accusation of bad faith. In that case, we have a deeper issue. Assuming that it's a real question asked in good faith is actually the weakest plausible interpretation, because the link makes it a self-disproving theory. Honestly the tongue-in-cheek interpretation is probably the strongest one.

There's no way to treat it as a strong argument and as a real question asked in good faith.

Also it can be okay to downvote misinformation even when the commenter didn't do anything wrong.