When developing a new blockchain, we as a team chose Go lang over Java and other candidates, due to Go being (a) natively suited to concurrency - there are primitives in the language itself (goroutines, channels) that really help with reasoning about concurrency (b) super fast - build time, running, testing are all much faster that Java, this gives a far superior developer experience (c) shorter and stricter than Java - code is much shorter (less verbose), and there is usually one good way to do things, and even the code formatter that is bundled with Go is very opinionated - over a short time this makes reading other people's code far smoother than having to deal with different styles.
You should be aware that Go presently (v1.13) lacks Generics.