My problem with this hole is that it's obvious that Ron just wanted to build a blind par-3 hole because he thought it was an important concept or because it would generate discussion, and he forced one into Erin Hills, instead of waiting to find a good spot to build one later in his career.
Someone asked early on if those of us who don't like the Dell at Erin Hills like the one at Lahinch. Well, the Dell at Lahinch is one of my favorite holes in golf. It's a completely natural idea -- you try to hit it just over a big dune into a little pocket between the sandhills. If you miss the tee shot, there are all sorts of carom shots which might be played for a recovery. [I learned that by sitting off to the side and watching people play the hole for a couple of hours one day.] It is impressive to look at and fun to play.
The Dell at Erin Hills has nothing to hit over. It feels like it calls for a deliberate topped shot. It needs the alignment rock because without it, you would have no idea where the hole was. [I don't mean the pin placement -- I mean you would have no idea where the entire golf hole was, or you'd assume you were playing to the eighth green way off in the distance, which is probably what they should have done.]
There are no interesting shots that I could envision around the green on the Erin Hills hole. If you don't hit the green you just have a downhill pitch out of rough, no contours to take into play, no bank shots.