Garland/Jeff,
It is very possible that green irrigation only, as was typical on early 20th century courses basically converted us to the aerial game. If greens held, and the approach was rock hard, why not eliminate the chance of bad bounce with the run up? I know I would, if score mattered.
As Jeff says, I have seen cases where the green front is too soggy to allow the run up, but this is actually more prevalent with green irrigation AND greens draining to the front. In the last few years, I often make a point of draining greens more to the side and less front, and where possible, away from the main cart path entry side, all to keep surrounds drier for golfers.
BTW, with part to part heads around greens now, and special controls for the fw approach, you would think we could control firmness in the approach, but its often tough. Sometimes, the fix is as simple as making sure all those part circle heads don't stop and reverse at exactly 90 degrees, where several of them sprinkle their end points in the exact same location.
But that it now.....then was then. I still think whether the entire green also has a side slope as well as a back to front affects play, with players knowing they can use the slope to get to the pin, and also knowing they don't want to short side themselves if the bunker is on the low side of the green. The slopes are much less than before, but with faster greens, the net effect and concept may remain the same.