I think the problem is that you're trying to analyze a work in isolation but then draw from it broad conclusions.
It would be kind of like taking Newton's Principia and using it alone to point out flaws in string theory, without taking into account all the objections and clarifications that have come to Newtonian mechanics in-between.
but isn't that what economists themselves are trying to do all the time - describe the whole of the world with either incomplete or unproven theories or both? at least we can see the results...
It would be kind of like taking Newton's Principia and using it alone to point out flaws in string theory, without taking into account all the objections and clarifications that have come to Newtonian mechanics in-between.