From a reader perspective I find it to be more cathartic to downvote an idea i disagree with than educational as a post maker that my opinion is unpopular. Especially if someone indiscriminately starts downvoting be because of a grudge. If anything it makes me think “wow these people are ignorant.” This is admittedly self-centered, but with anonymity on the internet, and a lot of the half-baked raw thoughts that get shared on forums like this, I get the perspective that’s what most posters would feel like when they receive downvotes. I’ve certainly witnessed it on Lemmy where people make angry comments calling out downvoters for downvoting instead of replying with counterpoints. I agree with your points in theory but from a behavioural perspective I think anonymous downvoting might discourage courage to post new or controversial ideas.