No; remarks like that have been vanishingly rare. The less-rare uses of "you fucking moron" or equivalent generally come from the person who asked the question, who is upset generally about imagined reasons why the question was closed (ignoring the reason presented by the system dialog). In reality, questions are closed for reasons described in https://meta.stackoverflow.com/questions/417476 , which have been carefully considered and revisited over many years and have clear logic behind them, considering the goals of the site.

It's just that those goals (i.e. "we want people to be able to search for information and find high-quality answers to well-scoped, clear questions that a reasonably broad audience can be interested in, and avoid duplicating effort") don't align with those of the average person asking a question (i.e. "I want my code to work").

I have heard so many times about how people get insulted for asking questions on SO. I have never been shown it actually happening. But I have seen many examples (and been subjected to one or two myself) of crash-outs resulting from learning that the site is, by design, much more like Wikipedia than like Quora.

Quite a large fraction of questions that get closed boil down to "here's my code that doesn't work; what's wrong"? (Another large fraction doesn't even show that much effort.) The one thing that helped a lot with this was the Staging Ground, which provided a place for explicit workshopping of questions and explanation of the site's standards and purpose, without the temptation to answer. But the site staff didn't understand what they had, not at all.