As an ignorant spectator I appreciate the balance provided by your comment. However, I wish you would have provided some concrete examples of which wheels they are reinventing, and how those wheels exist in other solutions.
Listen to this discussion[0] which highlights the point I am making. I set the marker for the relevant "container" comment but watch the entire thing to understand more fully what I and others are saying and why.
Container technology is grounded on namespaces and cgroups. Both technologies existed long time ago. Linux namespace is a very limited implementation of Plan9's namespace. Solaris and FreeBSD, to cite only the most famous, have resource limits database for process groups.