I may be cynical, but I don’t think we should make too much of an effort to cater to people who imagine that they identified a fatal flaw in a language that (1) they don’t really know, and (2) is otherwise widely used. Yes, they can be very vocal, but at the same time be safely ignored.
From a practical perspective my concern is about keeping this forum a pleasant experience for Julia users, potential or seasoned, instead of trying to convince people who just came here for an argument.
I think another potential “solution” is to find out a rough limit on how many replies there are in a normal post and set a maximum number of replies to every post before the thread automatically closes. This can be 50 for example or even a generous 100. An admin can then be pinged to undo this limit for a few posts if that number of replies is justified. If the OP then tries to start a new post to continue the flamebait, it can be reported and closed on the basis of flamebait with the evidence being the other closed post. We can even add to the community policy that we prefer short specific questions and discussions rather than long open-ended language X vs language Y wars. This can then also be used as a basis for closing threads. As for flamebaiters, we can probably suggest they use Twitter instead. Isn’t that secretly the purpose of Twitter anyways?
Let’s not call it catering to those people. I think it would save us a lot of time to have a post that works like your “help us help you” thread. One might say “we shouldn’t cater to people that can’t ask good questions,” but I think you rightly realized that it’s easier on all of us (and more welcoming too) to have a central place to direct people who are well intentioned, but lacking some knowledge.
Something similar for the known pain points new users may encounter wouldn’t take all that much effort to set up (those of us that have been around a while know where a lot of those epic threads and issues are), and could save us a lot of time when these sorts of naive criticisms inevitably crop up. I for one will have an easier time avoiding getting hooked by flame bait if I know there’s a central place I can link someone too. “Thanks for the critique, you may find this useful” and move on.
I am skeptical that
by the people who start these threads.
AFAIK they already exist in various forms, eg
https://docs.julialang.org/en/v1/manual/performance-tips/
https://docs.julialang.org/en/v1/manual/workflow-tips/
https://docs.julialang.org/en/v1/manual/faq/
https://docs.julialang.org/en/v1/manual/noteworthy-differences/
The problem is that they are not read by some people, not even when they are referred to.
I wrote my first rust code last month, an addition to a library. My impression is that rust is a terrible language. Did I go to a rust forum and complain about how inferior rust is? Of course, not; that would be outrageous, immature, blinkered, etc. There is nothing new or constructive I could tell them. 99% of you wouldn’t do it either. I know my impression of rust after a bit more experience will be completely different. I’ll probably even like it. After a bit more experience, if something were puzzling, I might go to a forum and search for it, maybe lurk, etc. maybe even ask a question if I really thought it hadn’t been addressed.
But, a few people don’t have this perspective, maturity or whatever it is that prevents them from making these annoying posts. What to do about it is another question. Probably exercise forbearance, give benefit of doubt, even when there is not a lot of doubt. Finding a practical way to deal with it is the main issue. But, we should still be clear headed about what we are dealing with.
I think this is a good idea. It would be handy to have a pinned post like this for newcomers to see and for easy linking when the flamebait posts come up.
Perhaps not - I’m thinking of it more like “I can link to this resource, and then more easily dismiss the criticism as in bad faith if they don’t pay attention.” I could probably already do this now, but I feel like it would make my heart lighter 
Yes, that seems like a good way to do it.
Has tweaking the board settings for the initial trust level (Understanding Discourse Trust Levels) been considered? Maybe disallow any new topic posts rather than the default (I’m assuming that’s how this board is currently set) of 3, and tweak the criteria for going to level 1.
New users frequently join this site to post a question, and I think that should be as easy as possible; so I would leave trust levels alone.
I have great confidence in the “suggest unbundling, then close” approach. Looking back at the recent examples of topics this discussion is about (no, I am not going to link them), I expect that it would have dealt with most of them effectively.
It should be implied that “linking someone else’s blog post/rant about Julia” falls under this: everything can be discussed, but users should rephrase each point they consider relevant in their own words.
Anyone encountering this discussion: I expect that the following policy will solve this issue.