Mike Hendron,
Remember today, in addition to the Sand Wedge we have the LOB wedge.
There's no doubt that those old bunkers, without a sandwedge, were a more formidable challenge, but, perhaps that placed a greater emphasis on avoiding them.
As I reflect on it, almost inherently, medal play is probably one of the biggest culprits, in the element of "fairness"
A great score ruined by someone's inability to extract themselve from a deep or steep bunker.
In match play, loss of hole, in medal play, a score ruined.
I think medal play, more than any other factor, is responsible for the quest for fairness, and the softening of some of the great, unique and challenging features in golf.