Exactly... This is so true, and it's sort of reflective of the human condition. If you tolerate a wide gamut of responses, and abuse, you're going to get abused. It sucks, but it's reality. The same thing happens (though, sometimes to a lesser degree, sometimes more) in our social circles.

Boundaries are necessary in all facets of life. If they're not well-defined, then they're easily crossed and you're left trying to establish them after expectations have already been laid, making it difficult to push back. I know it's not easy, but sometimes it's necessary to say no and cut off abusive behaviors/people. This was one of the hardest lessons I learned years ago. Yes, you'll make some enemies. Yes, you'll upset people. It's necessary.

One other problem (at least that I've had) is attachment. It's difficult to detach from something you've put a great deal of time and effort into, and one of the threats that occasionally pop up are "do X or fork/hand the project over/give up" (or any other especially mean epithet). If they're serious about forking it, hey, let them. It probably won't happen—and if it does, what are the benefits for the community? Is it risking fragmentation? If you're detached, threats seem a whole lot less threatening. And we've seen what pressure campaigns can do with some success (xz) with burned out devs.

I may just be jaded and cynical.