That is a strange take. DC’s a crowded city. As a pedestrian, I don’t have the time (or honestly see the point of) making eye contact and having a little interaction with every driver whose path I cross. Think about it-if I’m crossing K street, is your suggestion that I do that four times in order to cross the street? And repeat it for every street I cross? And you also want the twenty or so people who are crossing the street with me to also slow down and do the same thing? And believe that the other drivers around you would be happy if we held up traffic to do so? I can just hear the chorus of blaring car horns I would get if I tried. I’ll glance over quickly before I cross to be sure that you’re stopped, then be on my way. Waiting for a hand wave isn’t really a thing that I’ve seen done here. That sounds more like a suburban thing to me.