Disclaimer: I'm not a native english speaker, so feel free to improve this question
People on this section are probably familiar with the difference between personal conviction and evidence based conviction.
Most of the time our society doesn't act on the basis of studies based on null hypothesis or formal verification. So one person or 10 thousand persons can be easily wrong and take years to get to rational conclusions.
After years of complaining about the impolite behavior of many users the community has finally achieved a very functional self organizational tool: https://stackoverflow.com/conduct
Why did it take such a long time to realize that high rep users being impolite to new users was harmful for the community?
In this section we are familiar with confirmation bias, self deception, rationalization, cognitive dissonance. So.. it's not a surprise.
Although it could hurt someone, it was pretty obvious that the main motivations behind many users which spend many many hours on SE network and behave like a Bastard Operator From Hell (BOFH) is probably not so functional.
Any serious test trying to evaluate the usefulness of those users with BOFH behavior would have shown that they were harmful, and also that their reasons were personal and not functional to the community. And probably a bit neurotic (not adaptable to the context).
Still SE has a lot of rigid opinions that are seen as dogmas. https://stackoverflow.com/questions/5792388/is-there-something-in-php-equivalent-to-linq-in-c
This question, which was voted as useful by dozen of users, is marked as "closed as off-topic" by 4 persons.
I am pretty sure that any experiment would show that closing those questions is not functional in any way to the community.
But the community reacts very rigidly to criticism.
So could someone please help me to improve this post in a better way?
I will answer to the questions posed in the first answer:**
The primary discussion over the years was not whether or not the community could be perceived as impolite or not, but whether or not this is a necessary evil to make the community work the way it does.
That was the bigger issue. Many OP takes as ipothesis and dogmas many assumptions. They confuse personal conviction with facts. They don't doubt that question like this are bad for the community. They know they are right. So they think are sure they are acting for the best.
The problem is that... also criminals think they are right.