If I disagree with something you post, I would much rather have a discussion about it, as perhaps the void of my ignorance will be filled by the perspective of another. Perhaps not everyone is like this, though.

I too have seen "ordinary" authors be consistently (and perhaps, without apparent justification) be downvoted to the point that they get the impression "you're no longer welcome here", and enquires as to why met with silence. That isn't helpful to anyone.

I rarely downvote people myself, but If I am going to, I am going to directly justify my stance in a comment to the top level post.

What is far more damaging to the platform (except in the case of obvious spammers) - is automated downvotes on authors because of some conflicting intersection of ideas (eg, one might say the sky is blue, the other might say azure) - an extreme example to be sure.