I guess for me one of the scary things the Holocaust Museum showed was the ease with which millions of people could be swept under the rug. I would posit that an ad which showed an ultrasound of a fetus followed by the sight of some blood and indistinct ground-up gore running down a drain would be more horrifying than the type of graphic ads discussed here.
On a related note, compare the shower scene in Hitchcock's Psycho with scenes from more recent slasher flicks. The latter are far more graphic, and yet the former is far more effectively horrifying.
You might be right, especially if it was on one of these.