Well, I concur with the points from the article, since while I don't like Golang as a language I really like its tooling (BTW I am really craving for a more powerful language that compiles to Golang. And specially I like the focus in Golang to produce truly static binaries (they're not even linked with libc!).

And while Golang may not be the fastest language out there, it is fast enough for most use cases. I mean, Python is fast enough for most use cases, and Python is one or two orders of magnitude slower than Golang.

So yeah, I think their compiler decisions are fine. They may or may not be the best decisions, however the article is not talking about the compiler part of Golang, so yeah it can still talk about "undervalued technology".