While I think there are lots of valid criticisms of Go (concurrency correctness is still hard and its type system is not very good for certain tasks), none of these are reasons to switch to JavaScript, as the author did. If he was struggling with goroutines and channels, he could still elect for a Node-like architecture (even making it single-threaded by setting GOMAXPROCS=1). If he needed generics and unions (as he cited), he switched to a language without them and without any static types at all (or a single static type, if you will); in Go he could have downgraded to `interface{}` which is analogous to JavaScript's one static type, and he would have only gave up type safety in the bits of code where Go's type system was lacking instead of everywhere.
I don't want to give the impression of overselling Go here; it's just that for the cited criteria, Go is strictly better than JavaScript.