Jim Kennedy,
The flaw may be in your assumption that the men in the picture were 6" tall.
The average male today isn't 6" tall, and 80 years ago I would venture that slightly over 5 feet would be the average.
If you've toured some of the old mansions built at the turn of the century, you're immediately struck by how small the people were, based on the scaling of the features in the mansion, from the beds, to the showers, etc., etc..
But, whether it was 10', 11' or 12', they were a hell of a lot deeper then the current bunkers.
Evan Fleisher,
It would appear, that for $$$$$ maintainance costs that the putting surface has willingly, been allowed to shrink.