OK, that's not really true. Mark is a sharp guy, and gets open source as well, indeed, better, than most. But he's completely wrong on his criticism of Red Hat (which Greg of the Fedora Project shoots down). His basic point? Because RHEL is a closed binary, it's proprietary.
What Mark doesn't recognize - either out of pretence (meaning, he knows better but pretends otherwise) or out of ignorance (because Ubuntu isn't yet being used in the enterprise, so he doesn't yet know better) - is that the so-called closed binary is an important requirement for making Linux work in the data center, and across the enterprise, generally. No one writes applications to the source RPMs because no one wants to do so. Enterprises buy Red Hat (or Novell's SUSE) because they want certified stability and performance. Application vendors write to Red Hat and SUSE for the same reason.
They don't want the brand of freedom Mark argues for. They want a product that works. And they have the same benefits of diminished lock-in that Mark tries to claim exclusively for Ubuntu.