Fair enough. Would it also be fair to say that we're "seeing" market direction after the fact (analyzing executed volume) whereas HFT MM, thru their algos, try to divine market direction by "testing" for market demand and supply in real-time?

In years past, the guys down on the floor had the book, could see demand and supply, and act accordingly. That sort of look is no longer available - at least not nearly to the same degree - as institutions got smarter about how their traders placed orders.