What I've experienced is that Kovid is consistently hostile to anyone who disagrees with him in the slightest. There is no attempt to shine light on the argument or defuse the situation whatsoever - it always ends with comments like "what do you want from me? you get this project for free! if you don't like it nobody is forcing you to use it! get off my lawn!!!".
Of course, the guy has the right to talk to anyone any way he wants.
But I also have the right to publicly call him out on that.
If you have a public, open-source project on GitHub, and you regularly accept and respond to issues/pull-requests/suggestions, you are obviously presenting yourself to the world. It is basic courtesy to not be hostile in such communication.
It is a problem for anyone trying to communicate with him.
If you don't count personal experience as relevant, that's fine, but I really don't feel like digging up a bunch of github links from years ago.
Are you saying I shouldn't voice my opinions, unless they consist of only praise? Nobody asked the original commenter to provide proof of Kovid being "gentle". If you're going down the "only facts" road, then each praise should be followed by "sources" too.