If there's a clearly bad/misinformed/rude take, they simply don't get voted on. They rarely have more than the single 1 vote of their terrible opinion/sharing.

It's common to see +10 to +30 on a positive comment, with the comment it's responding to at 1.

I don't disagree that it could be a bad thing, but I think it's about the community and its practice surrounding it as well. So far in my experience on the instance I participate in I've seen it be effective.

Also I'm not sure if this is a thing on Lemmy but on reddit there were downvote farmers. Downvoting could also actually encourage people to perform these terrible comments to accumulate as many downvotes as they can. Downvoting disabled removed this problem in its entirety. Reddit has this issue long before some of its other problems and it has only grown since, up til I left. I don't know what the state of it is now, and I'm not sure how big of an issue it even is on Lemmy. It comes down to finding the line between what is preferable.

All in all, I think there are good and bad things about not having a downvote. I do think downvote disabled helps some aspects (engagement, active/trending posts) but it could also negatively influence federated content (spam, bad actors). I don't think a comment being at -30 is any more telling than the same comment at 1 when it's surrounded by +30 upvoted comments. However, if someone actively sought out getting downvoted, that can no longer exist.

IMO trading having bad comments be visibly negative in order to prevent the downvote farmers is a reasonable exchange