Interestingly enough, I received this via email
Hey, I'm the guy who downvoted you stupidly on SE.
I don't particularly want my handle coming up on internet searches connected to this, so I'm replying anonymously here. Now, if you get a mod to dig into this, so be it...
Anyway, I honestly, genuinely read lots of your posts (over several months) and actually disagreed on many occasions. But I was too stingy with my SE rep to actually downvote.
Then, all this mess with SE betraying our trust etc etc happened, and I decided to quit the site, and suddenly rep didn't matter any more. And I saw a post of yours and remembered I had wanted to downvote you several times. So I did, all in one go.
It was an idiotic thing to do. Hopefully (for my sake), if I hadn't been so worked up about the broader SE collapse, I wouldn't have done something so foolish. I certainly regret it if I caused you any personal annoyance, it actually was about disagreement about content, plus stupid mishandling of the process on my part.
I wish you all the best IRL
So there you have it --it's just a random symptom of the larger societal collapse of the SE community.
I do kind of have to admire the fact that they remembered disliking eighteen different of my posts enough to want to downvote them, but not enough to spend the eighteen points of rep doing so... :o