The requirement of setting a GOPATH has been a major issue for Go users who installed the Go tools for the first time and got the “you have to set a GOPATH” error in their initial experience with the tools. Explaining the GOPATH is and instructing how to set this env variable were both distracting new users away from using Go. This was especially true for users who are not necessarily developing in Go but using go get to download commands.
Go 1.8 is introducing a default GOPATH. If you don’t set one, the tools will use the default.