Based on a quick look through the old photos in Stan Byrdy's book on Augusta National it doesn't appear the bunkers at ANGC ever had the long, hairy, fescue look. Nor did they originally have the high maintenance look of today's bunkers. Rather the bunker look was more natural, rustic and freeform akin to what we have seen in old photos of Mackenzie's Pasatiempo.
Regarding the 12th hole in particular, the 1932 version had a larger green especially on the left front side where a bunker was located on the left hand side between the green and water which jutted in somewhat at that point. The front middle bunker was in today's location and there was a solitary bunker built high on the bank behind the green. The entire green was much lower and closer the creek. In 1960 the green was raised significantly and moved back a little from the creek to provide the steep slope to the front of the green that exists today. The raised green brought the rear bunkers more into play at green level.
Those differences noted, I am in agreement with Dave's principal premise that Augusta sets the standard that others have followed and that this has influenced other courses around the country in the direction of a highly manicured high maintenance look and away from a more natural look. Augusta clearly sets the standard for perfect, green playing conditions and over time this evolved into the highly manicured look of today as compared to the more rugged, rustic look the course had when it opened.
Over time, even while Bobby Jones was still running the show, an emphasis was placed on top quality playing conditions and high standards of maintenance that toned down the rugged look over time. It is my supposition that the advent of tv, in particular color tv, provided the money and the incentive that caused the conditioning standards to kick into a much higher gear resulting in the extremely clean look of today and spread the influence of that look nationwide. This change is evident in the comparison of the 1950's photos to those of today.