JKM,
I don't think I can pick a specific day, but, I would imagine that the trend toward altering architecture to be "fair" probably occured during the same period that golf in the U.S. was transitioning from Match Play to Medal Play.
The concept that one bad shot, one bad hole could ruin an entire round, which it couldn't in Match Play, was probably "A" if not "THE" biggest factor in eliminating quirk or what was perceived as "unfair" architectural features.