From the closing paragraph, I feel like he’s under the impression that Rust-advocating contributors are putting Rust’s interests (e.g. “legitimizing it” by getting it in the kernel) above the kernel itself.
If we're going to be serious about who is being toxic, it's definitely Linus in this thread. Guy makes first mistake (by a very broad interpretation of "mistake". Perhaps "misunderstanding"?). Linus goes nuclear. And while his reasoning is sound, his argumentation cycles between threats, bad-faith arguments, and just plain old yelling.
What some people don't understand is that the Linux kernel isn't 'led' in any meaningful sense. But I suppose some projects don't need actual leadership? I once was recommended a Metallica documentary, because "It's amusing to see what emotionally stunted 40-50 year olds who have never had anyone tell them 'No' since 18 will do." That's the Linus vibe -- somehow we've limped along to here. Seriously, read the rust/rust-lang issues/RFCs. Those people sound like grownups contrasted to this.
By his own standards he’s been very polite and calm. Remarkably so I’d say.
He used to be way ruder in the past, then decided to work on that and be kinder.
You can clearly see that in those emails.
The fact that he doesn’t agree with somebody and articulates why doesn’t mean he’s rude.