This doesn't really have anything to do with the merits of the languages themselves, but rather with the rewrite being entirely vibe coded. If it had been from Rust to Zig instead of from Zig to Rust, I expect the exact same response would have happened.

Mostly unfounded in my opinion. They took the _exact_ same strategy that go did when they moved from C Go to a Go based compiler.

First they essentially wrote a translator that preserved the C idioms (so it wasn't idiomatic go) until they had byte for byte output.

Then they started changing code one by one to be more Go-based.

Bun is doing the same. Right now it is mostly a one for one translation of the zig code. Over time they'll make it more idiomatic Rust.