While they do present a reasonable explanation for needing to use a different language I do agree it seem painful and the type of decision that will lead to a f

While they do present a reasonable explanation for needing to use a different language I do agree it seem painful and the type of decision that will lead to a follow-up article in a few year: "Why we're ripping out Rust". In some sense it reads a lot like they just needed an excuse to use Rust. Not that Rust is a bad choice for the areas they list as possible candidates for non-java code, it's just a really odd choice for Java shop, but then again, so is fighting the GC. It is incredible fascinating work though.