Jon, I don't disagree with anything you say. And I'm certainly not arguing that the US handicap system is better.
But, it needs to be recognized that the US system, with virtually all scores being required to be reported, and only a very few being reported as Tournament scores and then only lasting longer in the system, produces a different handicap result than does the CONGU system. The US system is not better; it's just different and gives different results. US golfers do not play regular stroke-play or medal rounds, and that practice is not going to change. Our system grew out of that fact. The exact same golfer, shooting the exact same scores, would have different handicaps in the US and under CONGU.
So, with the increased mobility of the world's golfers, the governing bodies tried to see if there could be a common system that could produce a fair, comparable result in handicaps that could be used in international play. Maybe that goal can't really be achieved because of the different styles of play of golfers in different countries. We'll see how it works.
But the thing I believe is not proper is to continue to act like our differing systems currently produce a fair basis for international competitions. Most analysts believe that the CONGU system, only counting rounds played under the pressure of tournament play, produces a substantially higher handicap than does the US system (although this conclusion is just what I've been told. I can't cite any reported study).
Maybe a simpler solution might have been to try to generalize what the handicap differential between the two systems is on average and adjust handicaps accordingly when international play is involved. I would guess (with no analytical backup) that a 20% increase in US handicaps might be required. Given the fact that most play for anyone is not international, and that golfers are wedded to their own national system based on their style of play, this might have been a better result, and it may be where we go eventually.
As an aside, I wish I had not used the term "honest estimating." The US system doesn't use that term, but rather is more elaborate in its discussion. I was trying to generalize the more specific instructions, and I may have confused the discussion. For example, the US recommendation is to not putt out putts that don't matter, but rather to estimate if you would make more than half of a putt of that sort--1 putt or 2, never 3. I know there is the basis for cheating in this kind of estimating, but it is no worse than many other parts of the handicap system. Handicaps are to show the "potential" of a player; they are not meant to be an exact number based on average scores.