> "If I downvote a misinformed post the original poster won't know where they went wrong, and people who see a grayed post won't necessarily understand what's wrong with it either."
that's ok, the onus is on the downvoted poster to figure it out for themselves. usually that requires seeing a pattern over the course of a few downvoted posts rather than pinpointing it exactly from a given post.
most downvoted posts break one or more hn rules, but a few are downvoted ideologically, so a little resilience is required. strictly unpopular opinions can often be more tactfully rephrased and at least be accepted for discussion, if not agreement. this is a pretty good life skill to develop generally anyways.