I worked at one of the early "container companies"; and wrote large parts of an in house mostly docker-compatible container engine. It was going to be part of a container orchestration platform pre-k8s and docker swarm.

This guy is totally correct. We also used Go for everything -- as it was hot stuff at the time -- and also very frustrating to deal with early version. Dependency management nightmares, bugs in the runtime, etc.

He also had to have a C shim that got loaded first, or shelled out to.

The hype around Google tools was pretty fascinating. I felt like that was the primary reason around using such an immature language at the time. There were better systems languages around for that kind of work.