i think totally flat fairways can be a part of an interesting, minimalist course. what it does require, though, is an open mind or repeated play of said course. what is required to make flatness is interesting is one or two simple, demanding features (deep bunker, burn, o.b, etc.).
i'm thinking of the diagram of MacKenzie's "value of one bunker" sketch or some of the holes at Hoylake. What it requires is an intense study of playing angles.
When I was living up on Traverse Bay while working at the Kingsley Club, I would sometimes play 'beach golf,' a sort of pitch/putt deal on our little beach. The sand was firm enough to roll a ball on it, with the exception of the fluffy stuff closer inland, and it was also almost dead flat. There was a mini bay of water within the firm stuff and a wooden walkway heading toward the water along one end. I dug out nine holes with no 'sand moving', and I was able to create some pretty interesting situations using only a slight depression or the water or the wooden walkway or the fluffy sand but rarely a combination of any and never three features at the same time. This leads me to believe it could be done on an actual dead flat golf course--the kicker would be the ability to create enough different strategic experiences for the 18 flat holes to keep the experience from getting tiring.