Posts like this are major contributors to maintainer burnout. Whatever value they have as a signal boost is a rounding error compared to the harm they cause to individuals as well as to the culture as a whole. Please don't ever post things like this. If you're this frustrated that the people who make free things for you aren't donating their time to you in the way you'd prefer, grab a drink with a friend and vent to…
The world does not owe maintainers protection from negative feedback. They are not high priests of open source whose behaviour is above criticism because they "make free things". It sucks to be criticized, even as politely as in the gist, but it's part of being an adult operating alongside other adults in a complex domain where disagreement is inevitable.
In this case, requirements about code quality and even refusal of code likely to introduce bugs is being called "gatekeeping" which is complete nonsense.
If you refuse a merge request for good reason, you don't deserve to get shit on by some salty contributor who doesn't want to bring their PR up to your standards. This article seems to indicate that any PR intended to be helpful must be merged, whatever the cost in maintenance, because otherwise you're gatekeeping.
If you refuse a PR for bad reasons ("I don't accept contributions from Chile because I had a bad holiday there once" and more racist/sexist variants thereof) then you definitely deserve criticism. What's happening here isn't really criticism, though, it's childish ranting about other people not putting in enough free work for the author and how that is somehow damaging to the volunteers, disguised behind polite words.
I think the world owes maintainers no protection from real, useful negative feedback, but a lot of negative feedback is just people being angry that they don't get their way. In a civil internet, that kind of behaviour has no place being called "criticism" and being assumed to just be par for the course of open source.
I've decided I never want to be an open source maintainer exactly because of the entitled people who write these articles, and I don't think I'm the only one being pushed away from open source for this reason.