The issue I have with GD's top 100 listing is the assumption of a great many panelists make that so-and-so course that has been in the Top 100 in a repeated manner automatically deserves to stay. I am speaking specifically about courses that fall beyond the elite 25 and make up the bulk of the middle of the survey.
David's point about what courses get considered is a good one because if you really examine the turnover it falls to a great degree on the final 25 selections from #75 to #100. You have had situations whereby a course that has been in the ratings (i.e. Grandfather, to name just one), is dropped and then reappears later again.
I also believe that upscale golf, and in some narrow instances taxpayer owned facilities, get short shrift. Yes, it's apparent that winners of the Best Private seem to be likely contenders for top 100 considertion. However, I can easily make a case that there are plenty of public courses that can easily go toe-to-toe with these layouts and best them in several clear examples.
In my own state of NJ it was clear not more than 10-15 years ago about the dominance of private golf. That has dramatically changed and I dare say it has done the same thing nationally.
Quality architecture is not the sole domain of private golf and if those who do ratings actually do the digging / due diligence you will certainy notice what I talking about.
What often amazes me is that certain key metro areas have the ability to place "x" number within the top 100, but if you were really to examine the situation more closely you would see that these same courses have the advantage in being located in an area where more attention is usually paid to what is located there (hint, hint -- the NY metro area).
P.S. Any publication that inserts "tradition" is simply attempting a protectionist scheme in order to keep old name clubs as high as they are. Ditto the placement of ambiance! In many cases I can see how the category of ambiance tilts towards the private clubs because of the placement of all sort of bell and whistle features.
I also have an issue with any bonus points towards walking. Yes, I enjoy walking and will do when available, however, again we are talking about adding points that fall beyond the scope of directly related architectural and shotmaking characteristics. When you use these non-related categories you often find that with the margins so tight it is these categories that can often be the difference in either keeping a course among the top 100 or even bumping it further up.
How are these categories DIRECTLY related to architecture and the analysis of the type of shotmaking that is called for?
Lastly, I agree with David on his assessment of Rustic Canyon now, but I do believe that if certain key tweakings did take place at the course -- specifically elevating the tee game requirements on certain holes, the course would have a shot for consideration.