Linus Torvalds greenlit Rust in the kernel, and as a BDFL, he is the one to decide. He has no reason to be upset with any decision because ultimately, all decisions are his own.

If he didn't want Rust in the kernel, he would have said it, and there would have been no Rust in the kernel. It is also the reason why there is no C++ in the kernel, Linus doesn't like C++. It is that simple.

And I respect that, Linux is hugely successful under Linus direction, so I trust his decisions, whatever opinion I have about them.