The results improving the end user experience didn’t have much to do with the rewrite. Improvements in binary size and speed could be had with similar efforts on the Zig codebase. They spent extra effort to get those metrics to look good to sell the rewrite.
The memory safety aspects could be discussed. Arguably they could have had equally good memory safety by employing AI, tests and fuzzing (the Zig integrated fuzzer that the Zig team suggested they use, not just the high level fuzzing they were doing)
For this kind of project I do think using Rust is a good idea. At the very least because a project like Bun probably can benefit from a more mature language.
But I also think Andrew’s perspective of this process has been essential to understand what happened here, and though he could have been nicer with his word selection in a couple of places (he doesn’t have the clout of Linus Torvalds to get away with it), what he wrote absolutely needed to be said. I find it annoying that people dismiss it as personal attacks. If being a bad manager is the direct cause of a poor working relationship and bad engineering results, pointing it out is not a personal attacks. It’s essential context for understanding what happened.