It's important to remember the single most important thing that disinguuishes the Dark Ages from the Golden Age that preceded it and the eras that followed it (whatever name they finally acquire) .
That's money. Central to RTJ's pitch to hundreds of clubs in the 50's, 60's and through parts of the 70's was that he could build good courses cheaply, quickly and they would be cheap to maintain.
I'm old enough to remember the 50's and 60's. People had not forgotten the shocks of the Depression and WWII. My mother and father still haven't. Golf courses were closing up left and right until sometime in the early 60's when, for the first time since 1930, more golf courses were built than closed.
There were no budgets for fancy shaping, filligree bunker edges, beautiful framing, landscaping, etc. And given the temper of the times, an emphasis on difficulty. Manly men courses and the whole bit. It doesn't take an architect overflowing with talent to do hard.
I actually like a lot of Dark Ages courses. There are some good RTJ and Dick Wilson courses. But not many. I do think it was a stretch of bad road for gca in the US. But I'm not sure it was entirely the fault of RTJ and his colleagues.
Bob