First off, one job moderators have to do over and over is explaining people that they shouldn't care about the occasional downvote. Because it really does not matter. From all the experience I've gathered over the years here, I can honestly just tell you to shrug it off.
And I know that this can be hard. I've received (seemingly random) downvotes on old posts of mine too, but if there's no comment about what's wrong, or—according to my own perception—nothing apparently wrong with my post, I'll move on. If there is, on the other hand, then I'd try my best to improve the post based on the critique.
Sometimes, this doesn't help either. I've got a -1 on a post which I later fixed. I told the user who downvoted in a reply to their comment, but they never reversed the vote. Well, too bad for me, but the overall result is that the post is more accurate, and will in turn help more people when they see it. That's a great result for me, personally. And it's one of the most important reasons for participating. The -2 points? Who cares.
Let's get to some individual points…
Within 2 minutes, some other user hastily downvoted it, which means that it will likely never receive the responses it deserves.
First, what is "hastily"? It's also conceivable that somebody took two minutes to read your question, decide it wasn't good or useful, and then downvoted it. Also, I don't see the conclusion from A to B here. Just because a question has one downvote doesn't mean it will never get answers.
While questions under a certain net vote threshold (is it -5, -6, I don't know exactly) will not be shown on the front page—which clearly isn't the case here—I wouldn't say that downvoted questions will attract less attention. (In fact, I'm much more inclined to check out questions with a score of -1 than 0-score posts, to see what's wrong and how it can be fixed. But this probably also has to do with me being a moderator.)
Now I need to find another site on which to ask the same question.
This I don't understand either. Your question is still there and got a decent number of views (given the fact that you posted it in what's probably the time span with the least amount of traffic on Stack Exchange). You do not ned to post it somewhere else. I mean, you can, outside of the Stack Exchange network. Nobody can stop you from doing that, and after all it might increase your chance of getting an answer. All arguments for and against cross-posting aside, that's a reasonable option here.
I am starting to think this site has become a waste of time.
I'm sorry you feel that way. Certainly Stack Exchange—and we as a community—want to encourage users to become long-time contributors, and make that as easy (and enjoyable) as possible.
But let me also add that you've been a member for only twelve days, so naturally it'll take a bit of time to get used to the way things work here. This includes the voting system, which might be deterrent for some, but ultimately also very useful for others (including visitors). You're not the first to complain (does that sound too harsh?) about it. The point that's very important to take here is that votes are essentially just cast against posts, not human beings.
Given that so few people actually exert the effort to cast votes (or stick around on this site long enough to be able to do so), every vote has quite a bit of impact.
I completely agree with that. We should get people to vote more, and also to explain more about their decision. Leaving downvotes (especially on old posts) doesn't help anyone, unless somebody already stated what's wrong with a post. For questions, however, voting is often a little subjective, and therefore can often seem a bit "random", especially to the OP.
At the same time, we see very few downvotes on answers, because they carry a 1-rep penalty for the person casting the vote. This means that there is little incentive for people to downvote incorrect or outdated information.
There have been lots and lots of discussions around that subject, especially on Meta Stack Exchange. At some point the focus was also shifted on filtering out low quality questions, because they also often attract low quality answers. This came with a change in removing the 1-rep penalty for voting on questions, and I think the majority of users was happy with that change, even if it meant that questions would be downvoted more often, without explanation.
Is there any moderation for users who cast counter-productive votes?
Yes. By counter-productive, we mean votes that are cast against users, not posts. There are two main types:
Votes user A cast on random posts of user B, in a short amount of time. These are often revenge downvotes for something user B has said or done.
(Up)votes cast between user A and B. Typical case of sockpuppetry.
We have a way to reverse this counter-productive behavior and may also suspend the user(s) involved.
If so, how is it determined if a vote is counter-productive?
Well, that's the question that's unlikely to be answered any time soon. Heuristics help us in determining if votes are in one of the above-mentioned categories. That's easy. But "random" downvotes? A totally different ball game. I mean, think about an answer that's gathered 60 upvotes in the last 2 years. Now it's downvoted by someone. Counter-productive? Maybe. But it could have also been that the software the question is dealing with has changed its command-line interface and the answer just won't work anymore.
The downvote you received on your question? From your post I assume that you'd also see it in the "counter-productive" category. And while I understand where you're coming from—nobody likes getting downvoted—there's also that subjective element that no machine and no moderator can judge. 18 people saw the question, one really didn't like it and downvoted it. One gave you an upvote. Who's "right" here? (I'll just take a blind guess that the words "simplest" and "fastest" often ring the SUBJECTIVE! alarm bell in some peoples' minds. You may for example want to make the criteria more objective.)
And no, we can't force people to leave a comment when downvoting. This has been suggested hundreds of times, and the only result would be people posting nonsense comments if they didn't want to explain why they voted. And then we'd need a review system for downvote-explanation-comments, and so on. Talk about overkill right there.
What really matters, at the end of the day, is whether the question you posted isn't put on hold as being off topic (which doesn't seem to be the case) and you get an answer for your problem. Does one downvote change the possible outcomes of either of these events? I highly doubt it.