I suspect it is much harder to retrofit such a culture to an existing organisation than to have it that way from the outset.

With Valve, GitHub et al we see organisations that are trying to encourage novelty and creativity in their workforce. Many organisations are more interested in repeatability in their workforce. By which I mean many of their workers are basically following a workflow of some sort that requires just enough human judgement so as they cannot yet be replaced by a robot.

So I think you're right, not all organisations can work this way and some probably don't even want to. But I entertain myself sometimes wondering how they could. My personal favourite is thinking about how one might manage to get a government department to work like Valve/GitHub.