And like PHP, it will be criticised with the power of hind sight but will continue to be used and power vast swaths of the internet.
But what is the universally regarded theory that k8s contradicts? I don't think there is one.
The storage of apiserver essentially works as distributed Blackboard in a "Blackboard System", with every controller being an agent in such a system. Meanwhile the agents themselves approach their tasks from control theory areas - oft used comparison is with PID controllers.
The managed hosts and/or their tools probably helped negate damage/resolve issues quicker. However I think that the idea that "all you need is a couple of dozen lines of yaml and a managed provider" is exactly why it's headed down a similar path.
For a real world examples just look at every improperly configured S3 bucket leaking data. Every private key accidentally posted to github from a careless 'git add -a'. Every API that doesn't properly check auth. None of these are within the purview of a managed hosts responsibility.
I'm not even against K8 in any of this. Just making the observation that - like PHP - it is empowering entire groups of people to do things they otherwise wouldn't be able to do.