Where did anyone say no bunkers?
From the Golf Advisor article that Howard linked to:
What will never be on the Sheep Ranch are bunkers. NO BUNKERS. “Ben and I talked about it a long time ago,” says Coore. “Robert Hunter, in his book called The Links, back in the 1920s, said there would one day be a site with such interesting undulations, sand bunkers wouldn’t be necessary.”
The previous version of The Sheep Ranch only had a couple of bunkers.
It's not sandy underneath, and we didn't have irrigation to help hold the sand in place against the wind, so we decided not to have much sand at all. We only built the bunkers we did to see if they would hold up . . . which they did not. So I'm not surprised to hear that Bill and Ben have opted not to have any.
Of course that wasn't the most unique thing about The Sheep Ranch "before", so nobody paid much attention to it.