I believe this has been discussed in one form or another before, starting with the famous Vote Vote Vote Vote Vote Vote Vote post. Several SE sites promote voting occasionally too via a pop-up message:
I'm not going to point fingers and give any examples as voting is a private matter and everyone decides for themselves how they use this privilege. I do realize that voting is optional: you can vote or not; give up-votes or down-votes only; never vote on certain topics, but that's not what I'm after here.
I often see a good enough question (GEQ) with 0 votes and an answer already upvoted 5 or so times even though the answer has obviously been added later on the time scale. By GEQs I mean the question that is not an off-topic according to the site rules and/or the user demonstrated some effort in formatting, practical work or literature research. Somewhat trivial, boring and overloaded with math questions can also be GEQs.
This means that not only other users decided to take no notice of the question, but also the respondent doesn't think the question he or she answered is good enough for the site. To my logic, why answer the question that doesn't even deserve your vote at all? If the question is not GEQ, but you desperately want to answer it, improve it first, discuss the nuances in the comments, and once it's clear, answer and upvote it to demonstrate both the question and your answer belong here! A simple rule I'm trying to stick with: if I answer the question, I upvote it.
What's even worse is when the user answers the question and also votes to close it as off-topic or by giving the reason "Unclear what you are asking" (which in this situation doesn't make sense to me at all). To me, this is a nearly hypocritical behavior: there is no chance for others to add further answers unless they go through reopening procedure, which is rather tedious, and it automatically devalues the answer itself because if the question is considered bad/off-topic, then the answer is most likely also doesn't belong to this site.
I'm no psychologist, but I suspect that the rep points as they are displayed now – some numbers in the green square – do resemble currency, and money makes people happy. Also, upvotes demonstrate that someone noticed the problem, acknowledged it's significance and already showing minor support. With this in mind, upvoting GEQs by new users (and answering them, of course) we are making them a bit happier and increase the chance of them revisiting the site and bringing some more questions (hopefully, also GEQs) or even starting to contribute.
Could we please
press F to pay respects show users asking GEQs some endorsement by not forgetting to upvote not only the answers, but their questions too?
P. S. One last thing: sometimes the the question is poorly formatted, or written using confusing terminology because the user doesn't know how to describe the problem. I encountered a few cases when the question's score changed from something like -2 to +3 after the edit simply because at first it was hard to understand what the question was about either to poor typography on the screenshot or cumbersome writing, but at its core those were great questions. If you see the room for improvement, please do try to edit the question, it might be well worth it.