People do run Kubernetes on bare metal... but there's no denying it takes effort. That effort should be coming down over time, but unfortunately there's still a ways to go.
That's not entirely true. I attend meet-ups with engineers from a fairly large company whose name you would recognize who run K8s on bare metal. I know that's vague, but I don't know how public their infrastructure is, so I'd rather not speak out of turn.
You're absolutely right that it takes some effort.
Bloomberg runs Kubernetes on bare metal and one of my friends is an engineer on the project (but did not speak at KubeCon about it). They've got a relatively sizable install as well.
You're absolutely right that it takes some effort.