Please note that, although there are scores of anecdotes in this thread, precisely none of them link to any examples or give enough details to find them. It’s always like this with Wikipedia detractors; I don’t know why, but it is. Complaints and horror stories galore, but nobody will link to any of it, preventing anybody from investigating what actually happened.
Raising the issues externally comes off as petty, because the “evidence” consists of 50+ pages of inane bickering on talk pages, community post , etc with no clear narrative or verdict. It’s a unique community that leans heavily on hyper-bureaucratic and bespoke debates.
I could share > 5 severe cases that required weeks of effort to “resolve” . It would require nearly as much effort for anyone to draw conclusions from.
There are some index pages of some of the more notable conflicts & debates. If you can indicate that digging that up would be worth my time to help you understand more, I may be willing to help you out.
There's no such policy , but it's abused as a way to censor criticism over behavior, which itself is a policy (RUCD)
There were a couple instances where user conduct concerns were raised on their talk page (in accordance with RUCD), and that user used USERTALKSTOP to censor the concerns. The outcome is that me and the other users who were raising concerns received a temporary ban (one permanent), instead of the concerns themselves being attended to and addressed.
Worse than the ban was the hours and hours of inane dialog on admin pages, defending your edit history, account history, intentions, etc. And the UI is clumsier and noisier than the worst 1990s web BBs
You can see how a seemingly benign non-policy can be abused to censor even well-intended volunteers.
I'm still going to ask though! We might get lucky. Want to help out?
In the past, when I've tried to keep receipts on this sort of thing (which requires an extraordinary amount of effort, and is often only possible if you've anticipated that there would be a need to do so - since content is often deleted or archived without warning, and nobody ever enters an argument on the Internet with the expectation of talking about that specific argument years later) and actually presented evidence, I've been accused being "creepy" or various other forms of misconduct, and the argument is still not taken any more seriously. I've given up on presenting evidence of this sort of thing because the people who ask for it are not being intellectually honest, in my extensive experience. They don't care if you can actually prove what you're saying; they will ignore you anyway.
And even if, as you say, all the evidence has been completely deleted, an honest critique would at least point out the exact article in question, and summarize the details of the attempted changes.
But all the criticism in this thread (and elsewhere) always lack this. It is a mystery.
Are you familiar with what Larry Sanger himself had to say about the bias that has emerged in Wikipedia (https://unherd.com/newsroom/wikipedia-co-founder-i-no-longer...)?
e: another comment elsewhere on this post brought up another source: https://www.tracingwoodgrains.com/p/reliable-sources-how-wik... . I've read a bit of it and can generally endorse what's being said there. In particular, some specific usernames are cited and I recognize most of them, which in itself is telling. Other comments here suggested that Sanger's personal views are less than scientific, to say the least. I have not looked into this personally, but I don't think this in any way negates the argument about bias. (Nor is any political camp immune to pseudoscience.)
Also note that the issue is biases in there whole generality. Most data produced by the universe will just not attract interest of most human beings. Or at least, as finite beings, we have to pounder where we put our attention and can’t afford to study every single topic with the same level of scrutiny.