alt Hacker NewsNote that of course Jai's tooling is also written in C++
As to why Rust, there's actual historical information about why Graydon wanted to make it and why Mozilla decided to fund that work after it was started.
Jon has said the intent was that Jai would allow him to make more games, because C++ held him back so much. So, yeah, it would need to be superior to C++ in at least this way, and by at least enough to justify the effort expended, writing C++, to develop Jai.
It was a rhetorical question. I think anyone should be allowed to make any language they want for whatever reason they want.
And IMO C++ is painful enough to use that nothing needs to be "better", more ergonomic is good enough for huge productivity gains.