In all likelihood, if the patch had been a pull request, the pull request would have been ignored as well. Much like the thousands of pull requests that are often ignored by various larger open source projects. Ain't nobody got time to triage drive-by pull requests from unknown contributors, especially on large projects.
There's no easy solution. Much like the recent curl security kerfuffle, the signal:noise ratio is important and hard to maintain.
I think the OP's point here was that if it's a PR and it's ignored: you spent a bunch of time writing a PR (which may or may not have been valuable to you, e.g. if you maintain a fork now). On the other hand, if it was an esoteric contribution process, you spent a lot of time figuring out how to get the patch in there, but that obviously has 0 value outside contributing within that particular open source project.
There's no easy solution. Much like the recent curl security kerfuffle, the signal:noise ratio is important and hard to maintain.