There is an interesting connection between downvoting a comment praising an observation about caricaturical behavior and the personality said comment is meant to highlight.
It's just that comments that don't add much tend to get frowned upon here. There's generally a lack of "agreeing" comments, the upvote button is used for that.
That could be it. I just wanted to praise the parent as it was a very clever and funny comment, which to me deserved more than "just" an upvote. But thanks for pointing out.
I think if you had said something like "I find this a very clever and funny comment, well done" it would have been better received, but I'm also just guessing.