Gents,
I have re-read this thread and remain convinced that it is mostly much ado about nothing.
For the record, in the last dozen or so remodels I have been involved in, only a few have added length to the golf course. Most are to improve maintenance, so overall, I can't say that length is ruining golf courses. A few of you have pointed out that your concern is with the handful of "classic" courses that are being extended for tournament play, which again is worrying about such a small percentage of courses.
Personally, if a course I designed in this era is considered in a few decades for a major tourney, and all they feel they need to do is add a few back tees, I will consider the design a real success! What an honor and tribute to the design of TOC that a few new tees is all that is required.
As to stronger athletes, while we say baseball hasn't changed, I do think the newer ball parks are bigger overall, unless they specifically shorten one field or another specifically to create more home runs. Its kind of like the driveable par 4. While other sports fields have stayed similar in dimension, I think there is pretty general agreement in hockey that the bigger ice would suit modern players better, but they can't change the existing stadiums economically.
So, the comparisons are not all accurate and every situation is unique. But again, when you start with the premise that we want our older courses to test modern players like they tested Hogan and Snead then we set in motion a whole lot of changes to keep things stagnant, which just goes against human nature.
Some worry about losing golfers to longer play times, cost, etc. which are very valid concerns. But how many of those came to the game once they thought they could play better and hit it further? A bunch, I am sure!