Apparently a number of people here (at least three I encountered today) need to find out the following.
If you are in the habit of down-voting postings without explanation when you think something is wrong with them, then here is what will usually happen:
- You will deprive yourself of the opportunity to find out that your reason for thinking there was something wrong with the posting was mistaken. If you post a comment that says something like "This question, or this answer, is bad because$\ldots$", then those who know will be able to explain to you why you're wrong about that and you will learn something that you can use later when judging others' postings, and elsewhere.
- Less often, you will be right in evaluating the posting as bad, but the poster will fail to find out what was wrong with it since you didn't explain that. Thus the frequency of such things will not diminish. You will have squandered an opportunity to help someone learn what is appropriate on the site and you will thereby contribute to the frequency with which bad postings appear.
In the course of accumulating a reputation of more than $150\,000$ (one-hundred-fifty thousand) on m.s.e. I have rarely received a down-vote and seldom down-voted other things. I have often posted a comment explaining that questions posted to m.s.e. should not be phrased in language suitable for assigning homework. It's not unusual that newbies need to find that out. When a question gets closed on the ground that it's not about mathematics when in fact it is about mathematics, and gets a bunch of down-votes without that simple explanation, the user does not find out what is wrong with the question . Fortunately, the prevailing activity on m.s.e. is not like that, as it is here on "meta".
Exercise: Figure out why $(1)$ will occur more often than $(2)$ with those who are in the habit of unexplained downvoting.