Yet another bait and switch plays out - build clout on the goodwill of open source and execute the plan at the opportune moment.
I may understand the decision but I sure as hell don't respect it - cashing out and prioritizing your family, a very human thing to do, at a glance it almost even seems noble.
It tends to be a spectrum, but the various, sometimes very different licenses adopted by the OSI still have something in common - the open source values laid out in the Open Source Definition. [1]
SSPL did not comply with this requirement, as it discriminate against specific users or use cases. I think it is in the interest of everyone to draw the line somewhere.
Open source licenses might be a spectrum but it's likely that the legal reality isn't. Like the famous double split experiment there's probably no spectrum and only a couple of buckets of legal validity.
Kubernetes for sure. When anyone asks for a good place to get started with understanding k8s - I tell them the docs should be all you need, then go get hands on.