I don't see why you call it religious. One can endlessly discuss pros and cons of using C++ in the Kernel, but in the end it's about either making a bet on C++

I don't see why you call it religious. One can endlessly discuss pros and cons of using C++ in the Kernel, but in the end it's about either making a bet on C++ or not; it's not that one can or has to formally prove that the bet is right to avoid being called religious. Linus listed cons that he finds important (which are real) and decided not to bet on C++. Linus has a long history of successfully managing Kernel, I think this makes his bets worth something. So yes, passing Linus filter is a great success for Rust, and even greater given that C++ didn't pass. Also, the fact that C++ succeeded somewhere doesn't disprove this claim.