This may be somewhat duplicate, but I think the issue still stands on its own compared to others.
I've noticed a depressing trend for new users, who often write poorly formed questions, having their questions downvoted without any explanation. These people are often used to simple forums where they just stick up a simple question and get a simple answer. Admittedly they should take the time to get their heads around how Stack Exchange works before posting, but often they don't know any better.
I agree that bad questions should be downvoted, but downvoting without an explanation is completely unconstructive, it doesn't help the user improve their questions because they have no understanding of why they were downvoted, and I imagine many simply feel ostracized for being new (which is not an uncommon phenomenon on the internet)
Is there anything we can do to get people to explain their downvote, or help the user improve their question?
I know this is a bit of a stretch, and that SE already asks you to justify your downvote, and that plenty of people already "do the right thing", but if there's anything more we can do to help defend new users from unconstructive downvoting then we should try and do it.