This maintainer is pulling rank on those below him. He is causing people making good contributions to Linux to quit the project. Yet he cannot handle his own decisions being overridden and he is attempting to force his agenda by threatening to quit.
His says that he cannot abide by a mixed code base and that, if that is the way Linux goes, he will “spend his time doing something else”.
Well, the time for that argument was a while ago. It was already decided to make Linux a mixed code base. If this maintainer is saying that he cannot support this decision, he needs to go at some point. What makes him better than all the people he is causing to quit?
If Linus does let this stand, it is a total failure of leadership.
The Linux Project either needs to accept technically sound Rust contributions or it needs to acknowledge that it is abandoning its Rust experiment.