I've noticed recently that fully valid questions have downvotes on them. That's fine, people can disagree with a question's intent/formatting/validity on the site. But they seem to be completely valid questions by our site's standards.
My thought is that after say, 3-5 downvotes in a day/given time period, perhaps the system should not allow that downvote without a comment as to why. I'm not suggesting that every downvote be paired with a required comment, but if a user/s is serially downvoting, then perhaps the system ought to force them to post why they believe the downvote is needed. This will probably just lead to people posted a keysmash for the downvote reason and moving on, but that doesn't mean we should do nothing/shouldn't talk about it.
Progress towards better questions and answers will never be made unless we figure out the reasoning behind those votes. I understand that this is not likely to be a popular suggestion, but it's also very discouraging for newer users to get downvoted immediately; this isn't a community for existing users and veterans, it's a Q&A for all.