Certainly watering the ---- out of greens in modern times has discounted the value of bunkers behind greens, and therefore their use by modern architects.
Also, golfers' clamor for every bunker to be visible has worked against these hazards. (Those Trent Jones "flash bunkers" behind greens are pointless as hazards, because they seldom leave a difficult recovery.)
Combining the two factors above, and Donald Ross's argument about discouraging bold play, I've rarely built hazards behind greens. (In fact, I've more often put chipping areas behind greens than hazards.) But I have done a couple of really good holes with trouble behind. That pot bunker on the 7th green at High Pointe is still the making of one of my best holes (even if it doesn't see so much play now that the course isn't firm). We also put bunkers behind several greens at Pacific Dunes -- 1, 3, 4, 8, 16 and 18 -- and some of them are real doozies. Texas Tech will have some, too, since it's a windy environment.
I've often hedged on whether to restore the back bunkers on Macdonald/Raynor courses. The cavities are still there, but why spend the money to put sand back in them? You can't see them, and for good players it's a tougher recovery shot without the sand.