Why do some people on Stack Exchange seem to only denigrate users on here?
To a large degree, that basic assumption is a big misconception.
Sure, sometimes people are annoyed, and they let that emotion guide their communication.
But: when we just look at those users who write impolite (or worse: rude) comments, you will find one thing: they do much more than "only denigrating" other users.
Those people that write such comments, those are the active users who try to uphold quality. And who probably look for interesting, well-written questions worth answering.
So, pro tip: every time you find a user who gives such a comment, you should do two things:
- flag the comment for being rude (and later check your flags, to see if the moderators agree with you!)
- but then click on the link that takes you to the profile of that user
Then: study how many answers that user wrote. Probably dozens, most likely: hundreds. Look at the counters how many times that user voted, or edited other posts. Chances are: pretty high counters. Meaning: most such people are contributing lots and lots of answers and moderation work. Day by day by day.
What I am trying to say: those people who come back and give you comments (even when their language is too aggressive), those are the people who made you come to this place. Because, in the end, you are looking for volunteer experts who are willing to spend their free time to help you with your problem.
So, just for a second, look at this from that perspective. You come to that place so that highly experienced professionals help you for free. But when they say something that you dislike, all of a sudden, the same people "only denigrate" other users?!
And to explain to you why that rudeness happens (been there, unfortunately done that plenty of times): out of frustration. In contrast to popular belief, Stack Overflow isn't programming school. It is a place for professionals and enthusiastic amateurs. And when you are an expert, and you look for interesting questions, and then you wade through endless endless waves of "plz do my homeworks for me" and "I need answers with code and explanations ASAP"... at some point, you snap.
And as wrong as it is, you might unload your frustration onto the next question, albeit that question is just "slightly off". We are all just humans here.
Long story short: it is wrong to be rude to new users. But that works in both directions. Being a "newbie programmer" isn't an excuse to come in unprepared, with unrealistic expectations.