Althouse has the Dove ad which is stunning in its failure to recognize its racial aspects. She asks, "How does an ad like this happen?"
Good question. My guess is that, as with many other ads, the focus on a clever aspect misses the unintended negative messages. Another possible reason: put bright people in a room and they may assume that the other bright people will notice any problems. When no one else says anything, that means it must not be a problem. Not a sound assumption.