The only dumb question is the one that isnt asked.
Is downvoting questions constructive?
I came across this question today and it had a couple of downvotes before I answered it. This got me thinking.
The downvoters left no answers, nor any comments. They simply clicked the link to the question, read it (I assume), clicked the downvote icon, and finally left. I see this behavior very often on this site.
The question in the post is valid in every sense. It should not be closed as it meets all the requirements for a question on Superuser. It is not a duplicate (that I know of). It is on topic, as it pertains to computer hardware. It is crystal clear what he is asking. It isnt too broad or opinion based, as it has a clear and concise answer. It should not be flagged either. It isnt spam. It isnt rude or abusive. The question is not of low quality. Nor does it need moderator intervention.
While this question is not technically challenging, or complex, I believe it is an excellent question. Anyone who reads that question can clearly understand exactly what he is asking. Based on that question, I was able to give him a definitive answer that he was able to accept. Other people coming to the site can read that question, see the answer, and learn something new.
So why the downvotes? The only reason I can think of is that the downvoters assumed this question was "common knowledge." Is it common knowledge though? A user commented on the question with the wrong answer.
Sadly, these "driveby downvoters," as I like to call them, are not uncommon on this site - as well as others on SE.
What do downvotes on question accomplish? Assuming the question meets all the metrics of the site, nothing. Well nothing positive, at least. The poster of a downvoted question might be discouraged and remove the question. Also, the poster might be discouraged and not ask another question. Doing this doesnt help anyone. The purpose of a Q&A site is to provide answers to questions, which other can learn from. If there are no questions, there is no reason for this site. This goes double for the recent initiative to encourage and help new users.
Personally, I never downvote a question and I think it should be removed.
I want to point out that I dont have an issue with downvoting answers.