I think the argument of the article is to pick the right language in the beginning so you save both developer time and runtime and don't have to rewrite in a be

I think the argument of the article is to pick the right language in the beginning so you save both developer time and runtime and don't have to rewrite in a better language later. For example, Python is a lot slower than threaded C, but quicker in terms of developer time and is memory-safe. If you pick one of the newer JVM languages though, you can get far closer to C than Python in performance once the JVM is running and still keep most of the expressiveness.