Earlier quoted context omitted.
The impression I've had from trying to contribute in the past has been that some editors will fight tooth and nail to prevent changes to an article they effectively own. The maze of rules and regulations makes it far too easy to simply block changes by dragging everything through protracted resolution processes. Even something as clear-cut as "the provided source doesn't support this claim at all" becomes an uphill s…
The trick these days is to calmly make your case on the talk page first for anything that might be even slightly controversial, before you attempt any editing. So if someone wants to "own" the article they have to engage on the same terms, or you can just point out the lack of opposition and make the edit yourself.
I've also noticed that a few of these editors seem to be deliberately abrasive towards new users, perhaps with the hope that they'll break a rule by posting insults in frustration. The moment that happens those editors quickly run to the site administration and try to get said user banned. Wikipedia's policies are increasingly treated as a weapon to beat down dissent rather than a guide on how to contribute positively.