Yes, I noted that in my post. I guess I meant general purpose virtualisation running on general purpose, commodity hardware.

Back in the late 80s spent 18 months in a role where I was developing scientific software on an IBM System/36 under VM/CMS. While this system actually had a hypervisor (CP) running on the physical hardware, and itself running virtualised instances of the CMS OS, it never felt (in hindsight) like I was in a virtualised environment. It seemed more like being logged into a multi-user unix box where everything ran in the same kernel - perhaps because the mainframe virtualisation layer was completely invisible to me, and everyone on the mainframe saw the same OS.

But point taken.