And people disparage them for it, which is nuts. Google had a problem that they determined could best be solved by creating Go. So they did it, and presumably, they've solved their problem. That seems like a perfectly good use of incremental improvement.

Which raises an interesting point: what to people on the outside looks like a paradoxical combination of insane hubris and deep technical conservatism is probably simply what to Google's eyes looks like steady-state, responsible technical problem-solving -- c.f., hhvm and Facebook for a similar approach.