Java is too advanced for Go folks, it is a PhD level language, when compared with Go minimalism, and their disdain for modern type systems (modern as in, invented in 1976, e.g. CLU and ML).

Also it is quite ironic how given the Java bashing on Go community, there was so little learned from Java evolution and design mistakes.

They even ended up having to reach for the same folks that helped designing Java generics.

As for your remark, the actual rewrite history as told at FOSDEM, is that the rewrite only happened as two strong minded Go devs joined the Kubernetes team and heavily pushed for the rewrite.