You'll never be able to agree on where that line should go. First because there's a cultural component to it. I'm from Spain so I can only talk for myself, but while he uses rude language, nothing I've ever read from him ever seemed particularly offensive. And second because any activity involving a large group of people will need some amount of toxicity if only to prevent other toxic people from derailing it, and since nobody thinks of themselves as the one that is being toxic to the project, there will always be some friction. You might not like fevers either, but they are necessary for a functioning immune system.

I seem to remember reading somewhere that, even at his worst, Linus limited his toxicity to professional-programmer kernel contributors (i.e. people who were employed by linux distros or hardware companies to contribute to Linux). Can anyone else remember/confirm this?

Regardless, to a newbie potential kernel contributor, that high level of toxicity can be intimidating, and the professional-programmers-only aspect is non-obvious, so it's easy to see why this would discourage hobbyists/free-time programmers from contributing.

Torvalds didn't even come close to toxicity shown by marcan on social media, so your diction is downright dishonest and spreading FUD (conveniently, marcan deleted all the generated drama from socials).

Asahi founder (plus community community) was heavy with drama and loved to attack and brigade anyone that didn't immediately bow down and listen to demands of their team and social media entourage. This isn't how the most important OS in the world should be led and Torvalds was right to call out that toxic behaviour.