Closing the door for beginners makes this community even
more elitist; and theres really no need to do so.
Allowing too many trivial threads has exactly the same effect, of limiting the appeal of the forums, just in a different direction. I guess it's a question of whether the site is aimed at experienced programmers, who are prepared to do research but need some resources to help them with OS development, or beginners who don't understand the way that strings work in C and can't be bothered to read the Intel manuals to determine how the stack behaves with different sized operands (and different processor modes).
I may have misjudged the aims of this web site.
You haven't misjudged the aims (plural) of this web site, you've assumed there's only one aim. Specifically; you've assumed that we're only here to help experienced low level (C, C++ and assembly) programmers become OS developers. You've completely overlooked the fact that we're also here to help experienced Java, Python, C#, whatever programmers (who have never had a reason to care about things like pointers, memory management, assembly language, IO ports, device drivers, etc) to become experienced OS developers.
You've also completely misjudged the level of experience. I'm happy to help anyone with at least some experience (as long as they're willing to learn, including being willing to learn to find things in datasheets and CPU manuals if they haven't developed that habit yet). You seem to want to require a computer science degree.
Those beginners you're complaining about? If we treat them with some decency (rather than telling them to go away and read a 3500 page manual in the rudest way possible), then within 1 year at least half of them will become very valuable members of this community.