There are many examples. Attempts to make technical pages more accessible to a general audience have been shut down repeatedly and resulted in a separate Wikipedia entirely called "Simple English".
Attempts to neutralize any page that anyone pays attention to results in the page's regular babysitters coming out and destroying it -- a normal person can't compete because these people are obsessive about the pages they watch, often because their full-time job is to ensure that clients' Wikipedia pages read in the manner desired. Sometimes other motives, like zealotry, contribute to the obsession.
These persons become steeped in WP-specific jargon, utilizing an ever-growing body of subjective and sometimes almost conflicting rules to crush any opponent who doesn't come ready for the fight. They'll say that your edit doesn't comply with WP:XYZ and WP:ABC, you'll say it does, etc. And even if you do come prepared, unless you're willing to commit more resources than your opponent, they'll just quietly change it back with a non-suspicious commit message after a few days, once you've decided you had other things that deserved attention. Worse, often these persons become administrators and will ban you for "incivility" or protect the article so that their preferred version remains in place. You can begin an appeals process, but again, it's something that's going to be difficult to reasonably affect without a major time commitment and even after you win, it's typically something that can be easily undone once the attention of the relevant appeals committee is diverted.
It's impossible for a normal person to compete with that type of editor, and they are very widespread. I don't necessarily want to give specific examples because I was involved in all of the ones that are significant to me, but it is not hard to find this occurring. You may want to reference the historical archives for The Wikitruth, as they had extensive case studies on this type of failure.
Without either agreeing or disagreeing with your comment, I'd like to point out your case would be stronger if you actually provided a concrete example like the GP asked.
I referenced places where the GP can find concrete examples, other posters have given links, and I've explained that I don't want to wake sleeping dogs and get into specific controversies that I was involved with, which are the primary source of my observations. I believe that is sufficient.
>Attempts to make technical pages more accessible to a general audience have been shut down repeatedly and resulted in a separate Wikipedia entirely called "Simple English".
I am somebody who goes to Wikipedia by default when looking up something, even if it's something technical, although I know that I won't get much use out of reading the article, and it is precisely for that reason.
It seems that the Wikipedia community has assumed that being able to write in "Standard English" means the articles can be as complex and technical as they wish.
I have often put myself in the mind of somebody who knows only, for example, basic networking, and tried to rewrite networking articles (or at least their introductions) to make it easier for them to understand the core concepts. Instead, the admins think it's wiser to have the first paragraph use a jargon word every other word since the reader can always click that word to be taken to its article.
It is also true that if you're going up against an admin's article/edit, their say is final and you've pretty much wasted your time.
