Seems to be advocating more for thoughtful criticism (and meaningful discussion) than anything. Is it going to make things better? To what degree, I don't know, but I'd imagine it helps with people creating pull requests and then disappearing from the project (which I've seen multiple complaints of this behavior over the years). It'd make them feel more of a stake in it I'd imagine if they're not receiving blowback from the maintainer for daring to create a pull request (based on the "bads" in the examples).

I've personally never seen anything as bad as the examples given (I've read stuff from Linus that are there, but seems like he's trying to change the atmosphere there now), but if the communication is that prickly, I can't imagine it is going to receive a ton of outside help in the form of pull requests (that could be intentional though).