I think a big part of it is the change in public perception. Bunkers are now not viewed as a challenge to the player, but as an annoyance to "ruin" your round. I saw a commercial today that put it roughly in those terms. I wish I could remember the exact wording. It as an ad for a new GPS device, SkyCaddie? They really emphasized negating all hazards, especially bunkering.
Does this futher advance the devolution?