Peter,
I believe some of the charm of older courses is that, over time, they have managed to create shot challenges that may not have originally been intended. And not just famous ones, the kind of "under designed" course we see so often. They might have steep banks around the greens because they wanted to save initial construction cost. Yet, when you are faced with a delicate chip where you must just carry to the fringe to stay close to the pin (or on the green) its a great experience, regardless of the designers intent. (which was probably to save money, get it grassed, and get the course open and revenues flowing...…)
Or, when you know you have to be "below the hole" due to green speeds never imagined. It's purely random, and certainly not anticipated by any architect as something to design up.
Might be just me, but I think some of the unseen, not obvious architecture arises just because of the random place your ball lands, relative to where the pin is set, etc. It's not obvious until your ball lands in that exact right place to reveal it, LOL.