Оказывается, комментарий на Хабре, о котором я писал, это перевод вот этого комментария. У него, к слову, больше дизлайков, чем лайков, т.к. написан AI. Но, судя по всему, портировать (именно портировать, не переписывать) TypeScript на Go всё же легче.
В самом низу есть и ответ Андерса Хейлсберга. Приведу цитату:
The TypeScript compiler's move to Go was influenced by specific technical requirements, such as the need for structural compatibility with the existing JavaScript-based codebase, ease of memory management, and the ability to handle complex graph processing efficiently. After evaluating numerous languages and making multiple prototypes — including in C# — Go emerged as the optimal choice, providing excellent ergonomics for tree traversal, ease of memory allocation, and a code structure that closely mirrors the existing compiler, enabling easier maintenance and compatibility.
In a green field, this would have been a totally different conversation. But this was not a green field - it's a port of an existing codebase with 100 man-years of investment. Yes, we could have redesigned the compiler in C# from scratch, and it would have worked. In fact, C#'s own compiler, Roslyn, is written in C# and bootstraps itself. But this wasn't a compiler redesign, and the TypeScript to Go move was far more automatable and more one-to-one in its mapping. Our existing codebase is all functions and data structures - no classes. Idiomatic Go looked just like our existing codebase so the port was greatly simplified.
Короче говоря, это техническое решение обусловленное финансовыми ограничениями. Переписать на Rust/C# можно было бы, но кто за это будет платить?