I do think highly of Rob Pike and Ken Thompson for their IT work, but they are simply not good at language design, which just shows that PL design is quite unlike working on an OS.
Both statements, because unless otherwise qualified you're comparing apples to oranges when you say Java compiles as fast as Go. There's always going to be more overhead on running the Java bytecode on the JVM than there will be when running the native instructions generated by a compiler (even as "unoptimized" as Go is).
And someone that makes that assertion with a straight face without this caveat is not someone that should be dissing Rob Pike about language design.
I do think highly of Rob Pike and Ken Thompson for their IT work, but they are simply not good at language design, which just shows that PL design is quite unlike working on an OS.