Jim -
The most recent round of changes to ANGC were triggered by Woods' '97 winning score. People saw more of that coming. Frankly, I think they freaked out.
If you start with the assumption that the USGA is paralyzed in the face of technological changes (which seems a safe assumption), I am not suggesting that classic major venues do nothing. The easy, least bad option is to lengthen tees. You can still play the course from member tees, the physical changes are minimal, etc.
Making permanent changes are, however a different issue. When you narrow playing corridors on a course where one of its most important design features was wide playing corridors, things have gone badly wrong.
For what purpose has the course paid that price? To keep winning scores at The Masters at or around par.
To repeat myself, most people in the US believe such views are self evident. Beyond debate. But they should not compel assent atomatically. There is, for example, at least one very old golf organization that believes otherwise. Maybe they are on to something over there. One thing is clear. That old organization does not have a tack record of mauling great classic courses.
Bob