I found the link again, apparently Rob Pike had said:
The key point here is our programmers are Googlers, they’re not researchers. They’re typically, fairly young, fresh out of school, probably learned Java, maybe learned C or C++, probably learned Python. They’re not capable of understanding a brilliant language but we want to use them to build good software. So, the language that we give them has to be easy for them to understand and easy to adopt. [1]
But I think we should also keep Rob Pike's experience and wits in mind. It was probably intended as a humble witty remark. If you consider how complex concurrency is, and how Golang has made it simple with a single keyword to spawn coroutines (go) and a straightforward data structure (channels), I think he is right to say that Golang is easy to understand and easy to adopt.
[1] http://nomad.uk.net/articles/why-gos-design-is-a-disservice-... citing the quote from http://channel9.msdn.com/Events/Lang-NEXT/Lang-NEXT-2014/Fro...