The friction comes when somebody presumes to be in the know and discovers after a few contrary posts from those REALLY in the know that he or she is full of beans and has been called out for it. If the moderator can see that the subject individual is full of beans, why stop the discussion? The good news is that the situation does not come up that often, which, to me, argues in favor of self-policing unless and until the debate of facts or opinions turns into personal attack unrelated to the subject matter.
If it's pointed out that the person is full of beans and why and the person accepts that, the problem takes care of itself. If the person doesn't accept it but can discuss it rationally, the problem takes care of itself. If those scenarios don't happen, what's going to be accomplished by allowing 10 pages of people telling the person "you're full of beans" while the person gets more and more defensive until it escalates into nastiness? It's not at all about everybody being a winner. It's a food forum. Nobody wins or loses, not because of political correctness, but because there is nothing to win or lose. I'm not a big fan of self-policing on internet forums. Or rather, I'm not confident in most people's ability to do so. I think there's plenty of evidence in existence regarding people's (in general) (in)ability to moderate themselves on the internet when nothing is forcing them to. The fact that the situation doesn't come up often here could be tied to the fact that it's not allowed to happen. It gets stomped out before it gets out of hand and everybody knows that. Those that don't know it find out quickly. But I'm not asking anybody to agree with me, just throwing my 2 cents in the bucket as requested.
We are absolutely on the same page regarding there being no need for 10 pages of full of beans, and while the line between a little snarkiness and nastiness is a subjective one, nastiness for its own sake accomplishes nothing. Before we get to that point, I would hope that one or posters would chime in with "enough already", or if not, that is where a moderator can do some good by saying, "OK, we have established that most find X's position full of beans. Can we move on?" That is vastly superior to closing threads and deleting posts. If people on the thread refuse to move on after a time, THEN action may need to be taken. However, people occasionally pounding each other with fact and logic, as happens daily in almost every endeavor out in the real world, is the lifeblood of good online forums. Thesis-antithesis-synthesis, as it were.
Another point about deletion: it too often seems calculated to "protect" somebody or something. Silly to say it this way, I know, but it has the effect of saving face for people who may not deserve it by "destroying the evidence" of the stuff that was being spewed. It keeps the broader audience from making its own judgments regarding X's "bean content". (I apologize that beans, as delicious and nutritious as they are, are taking an unfair beating here!) On occasion, bullies are being protected, and there are times when the bullies are, in fact, the moderators. Finally, while there may be nothing to lose, I think there is, in fact, something to "win" by full, thoughtful and unfettered discussion, which is quite often the arrival at a superior way to accomplish something and/or debunking of urban myths or out-and-out BS. Sometimes the process gets a little self-righteous around here, and sometimes ego balloons can stand popping. I am suggesting that there is too quick a hook on that on eGullet, and it suffers for it. The ability of eGullet to attract new members may also suffer, but I readily concede that if, on the flip side, eGullet is perceived as a verbal war zone, members could also be lost. I find that most U.S.-based boards, chat rooms, etc. harbor a small number of whiny types who want to dictate and censor the thoughts and words of others so that any unpleasantness can be avoided. Such types rarely contribute anything of substance to discussions. Too busy refereeing. And like sports, calling the game too closely ruins it. It is why everybody hates referees! Your last few sentences are flat out scary. Stalin, Hitler, Saadam Hussein, take your pick, all got where they got because "it got stomped out and everybody knew that", eh? Hardly the same human impact here, but EXACTLY the same principle...