In the Go FAQ [1], when they list the purpose of the project, the first answer they give isn't about concurrency (as some might suspect), it's:
"It is possible to compile a large Go program in a few seconds on a single computer."
They've been consistent about this. It's a major design goal and, for some, compilation speed is worth more than support for Generics.[1] http://golang.org/doc/faq#What_is_the_purpose_of_the_project