Tom-I hope it didn't come off that I was trying to say there should be no 0's or 10's. I wasn't. I was trying to articulate what those two numbers mean to me.
What I was trying to say is that the 0 comes to mean a course that might not necessarily be bad by itself, but in knowing what went into construction (tons of money, vast amounts of land movement, whatever it may be) it should have amounted to something really good (certainly Shadow Creek was 100% man made, but done right, so you thought it was a 9) but wound up falling flat and being a huge disappointment (where Shadow Creek is considered by many to be something of a masterpiece).
And the 10 is something that might be the finest example of an individual architects work, or a course that falls perfectly on the land and looks like it was just mowed out of the timbers and weeds, or a course with otherworldly aesthetics.
These levels of greatness might be hard to quantify perfectly, however, they are known when seen, and they certainly do exist. 10 is not perfect, its just the top level that can feasibly be obtained. Same with golf, 59 is the golf standard of greatness over one given round, but its not perfect, 18 is perfect and on a regulation golf course, something that can't be obtained. The 10 is not perfect, its just as good as humanly possible, and there are a number of different ways to do it.