It's that sense of superiority that pisses me off.
Many maintainers condescendingly reply "contributions welcome" in response to user complaints. People like that had better accept whatever they get. They could have easily done it themselves in all their "high quality" ways. They could have said "I don't have time for this" or even "I don't want to work on this". No, they went and challenged people to contribute instead. Then when they get what they wanted they suddenly decide they don't want it anymore? Bullshit.
You're making the assumption that these are "high quality" projects, that someone poured their very soul into every single line of code in the repository. Chances are it's just someone else's own low effort implementation. Maybe someone else's hobby project. Maybe it's some legacy stuff that's too useful to delete but too complex to fully rewrite. When you dive in, you discover that "doing it properly" very well means putting way too much effort into paying off the technical debts of others. So who's signing up to do that for ungrateful maintainers for free? Who wants to risk doing all that work only to end up ignored and rejected? Lol.
Just slap things together until they work. As long as your problem's fixed, it's fine. It's not your baby you're taking care of. They should be grateful you even sent the patches in. If they don't like it, just keep your commits and rebase, maybe make a custom package that overrides the official one from the Linux distribution. No need to worry about it, after all your version's fixed and theirs isn't. Best part is this tends to get these maintainers to wake up and "properly" implement things on their side... Which is exactly what users wanted in the first place! Wow!
no, I am not obligated to merge badly written PRs introducing bugs just because I had no time to implement the feature myself
FOSS maintainers are not a unified mind. The people who go "contributions welcome" and "#hacktoberfest" are somewhere near one end of the spectrum, and the folks dealing with low-effort contributions are somewhere near the other end of the spectrum.
Thank you for a clear and concise illustration of why some contributions are really not welcome.
Just about the only thing I will agree with you on is that projects should indeed make it clear what the bar for the proper contribution is. This doesn't mean never saying "contributions are welcome", if they are indeed welcome - it's still the expectation for whoever is contributing to do the bare minimum to locate those requirements (e.g. by actually, you know, reading CONTRIBUTING.md in the root of the repo before opening a PR - which many people do not.)