Cliques, bullying, use of "policies" as a weapon, and the tyranny of the administration system
Wikipedia is a collaborative project. If you cannot collaborate with others, you do not belong here. It is like in If by Kipling: "But make allowance for their doubting too". This is especially relevant since quoting reliable sources does prove that a certain viewpoint is at least minority opinion, when there is no consensus (I am not speaking of fringe theories). Of course, it takes some critical judgment and some education in order to recognize a reliable source, especially when it is not published in peer-reviewed, print-published mainstream scientific journals. E.g. a Time interview with prof. Michael Coogan about his recent book summarizes the results of sound scholarship, although the interview is not itself peer-reviewed. This is due to the fact that Coogan is a respectable academic, and he can be trusted to render sound scholarship during interviews, debates, conferences and so on.
Collaboration is a two-way road. The complain here seems to be about poor desire to collaborate from the side of old-timers. Therefore, without judging the merits of the complaining person, I would suggest Tgeorgescu not use phrases like "if you cannot collaborate". Although I understand that "you" here is a placeholder, synonymous to "one", but the post reads more like turning tables than addressing the grievances.
The complaining person actually says that he did produce references. And here is the crux of the problem: while the facts come into wikipedia from sources published by experts, it is wikipedia community who has a power to decide who is expert and who is not. Of course, there is a policy/guideline w:WP:RS, but again, its implementation is by wikipedians.
That recognized, a human factor comes into play. Certain topics are of permanent controversy. There are millions of potential newcomers. And "old guard" becomes tired to repeat the same arguments again and again, becomes frustrated, speaks in terse bordering with brisk language, and thus antagonizes the likes of PRGuisi instead of educating them.
The solution is already known in wikipedia. I've seen that some (but unfortulately a woeful minority) talk pages briefly summarize major decisions about the content, sources, and counterarguments. However most of them simply store mile-length archives of bickering only dedicated pedantic historian would want to read. So when a newcomer sees the reply "We already discussed this and decided that...", it is just a hearsay difficult to verify, and since "wikipedia... anyone can edit", the newcomer even does not have to question the authority, since an individual opponent has none.
The only authority is the community w:WP:Consensus based on arguments. The consensus is supposed to be reconsidered when new arguments arrive, but the problem is that very often it is very difficult to verify that the new argument is new.
Therefore I would suggest to make it a policy to summarize arguments in controversial article talk pages. Once a summary is in place, it becomes a very simple touchstone to decide whether the new editor is worth of a new discussion or of a simple reference "see Section 3.1.7b of 'Decisions and Amendments, Part 4' ".