Here is Bobby Jones' description of the 13th, from GOLF IS MY GAME, published 1960:
"Number ten at 470 yards is a par four because of the favorable slope of the ground offered to the tee shot. We call thirteen a par five because under certain conditions of wind and ground, few players will risk trying for the green with a second shot. In my opinion this thirteenth hole is one of the finest holes for competitive play I have ever seen. The player is first tempted to dare the creek on his tee shot by playing in close to the corner, because if he attains his position he has not only shortened the hole, but obtained a more level lie for his second shot. Driving out to the right not only increases the length of the second, but encounters an annoying sidehill lie.
Whatever position may be reached with the tee shot, the second shot as well entails a momentous decision whether or not to try for the green. With the pin far back on the right, under normal weather conditions, this is a very good eagle hole, because the contours of the green tend to run the second shot close. The chief danger is that the ball will follow the creek.
The most difficult pin locations are along the creek in the forward part of the green. A player who dares the creek on either his first or second shot may very easily encounter a six or seven at this hole. Yet the reward of successful, bold play is most enticing.
Several tournaments have been obviously won and lost at holes twelve and thirteen. Others, upon careful analysis, will be seen to have been won or lost here, even though the decision may not have been obvious at the time.
This hole is a splendid example of what can be done by taking advantage of natural features. The splashes of sand in the woods behind the green and the azalea along the left side were placed there in order to add beauty to this natural setting."
Observations:
1. Bobby Jones could write well.
2. This was written in 1959-60, so Jones had observed play on the hole for 25 years, and wasn't stuck in his "original design concept". He was very happy with how the hole worked then.
3. He never mentioned any clubs a player might hit, only position and stance and risk and reward.
4. He didn't say anything about "maybe someday it will need more length" or "I wish we could have left a little more elasticity behind the tee" or "one day we will buy Augusta Country Club and make this into a really difficult hole again."
5. He did describe the second shot as being "a momentous decision" and that is where some mind-reader may base their rationale for changing the hole. [I believe Fred Ridley has already mentioned this.] While it is certainly easier to get there in two than it was in 1960, you are still taking a chance at blowing the tournament, aren't you?
6. Most importantly, those first four statements were statements of fact, while the last half of #5 is strictly opinion. You will certainly find people on both sides of it.