> In either case, the tragedy of the commons issue is well known in other guises throughout the history of philosophy

It really isn't. There are lots of anecdotes that appear to illustrate the tragedy, throughout history. But what they lack is what Ostrom added: the historical account of how a previously managed commons had its management structures dismantled by greed and power and only then was in a position to become a "tragedy". The result is that a very significant number of people believe that resources held in common always lead to "tragedy", when in fact the lesson is "the structures used to manage resources held in common are critically important, and severe action should and must be taken against those who try to dismantle them". We can hold resources in common, but must be ever vigilant and actionful against the selfish bastards who seek to manipulate them for their own advantage.