But Go's real strength is in its readability, not writability. I think it's very much possible to learn Go in a week, then read clean Go code like the standard library and understand exactly what's going on. At least that's my interpretation of what it means for a new grad to be productive in Go in less than a week. Nobody is expecting someone new to write production-grade libraries with intricate concurrency bits in their first week, but they're already productive if they can read and understand it.

As a rule of thumb we spend 10x more time reading code than we do writing it (code reviews, debugging, refactors). So why not optimise for it?