It is, but it is operating system virtualisation as opposed to hardware virtualisation. Instead of lying to the OS about the hardware it’s running on, you lie to the application about the OS it’s running on.
I agree that this is mostly what we end up with and it’s pretty ridiculous. I don’t think there’s really a Docker or Linux container runtime which adds overhead but does add complexity. I think it’s sad that SmartOS never took off which has containers running on the metal with proper isolation, as opposed to glued together Linux kernel components.
I think they are the solution but not the way they are implemented right now, and Linux will probably never get a really good implementation. That would look something like BSD jails + resource management, or Solaris zones.
