WSA you very well could be right. If we take archaeological reports from the Mississippi mount builder culture at face value, and hypothesize that the large skeletons found there were first of all BF and secondly were coexisting with humans during that period, one event happened which might explain BF behavior. The Mayan invasion is thought to be the end of the Mound Culture. One Mount culture burial site had large skeleton humanoids laid out with human size bodies in an apparent burial after a massive battle. It appeared that both were fighting on the same side with a common enemy. Mayans killed or captured enemies they encountered during their expansions. Since it is unlikely the small statured Mayans could have captured BF size tribes, what they could not kill outright, probably scattered to the winds avoiding the marauders. The Mound builders were studied by Smithsonian types and suddenly that research came to a screeching halt. The Mound Builders had an advanced new world culture, studied astronomy, predicted astronomical events, had pyramids, and one would think that North American Scientists would be interested in studying that. But it appears to me that something found shut that down. That Mound Culture flies in the face of the Manifest Destiny policy the Smithsonian supported, that Native Americans were nomadic hunter gatherers who had no real ties to real estate. Heaven forbid that the Mound Culture peoples rivaled the Mayans and perhaps the Egyptions much earlier. Throw in a giant people, religious beliefs at the time, especially within the Smithsonian staff, and you have something that the Smithsonian and the US Government did not want to be known. Archaeologists will travel half way around the world to study ancient civilizations in Egypt and ignore something similar in there very own back yard?. Why is that? Does study of the Mound Culture lead to BF? Is that the reason the Government refuses to acknowledge existence of BF? Does a big lie of Manifest Destiny in the 1800s lead to cover up since? Does present day discovery of BF lead backwards to the big lie and cover up in the 1800s? Would the public or scientists demand to know what happened to all the big skeletons? You can be sure they were examined and lab notes created at the time. Are they hidden away in the bowels of the Smithsonian? Or have they been destroyed?
All of that is my personal conjecture, based on history, and what is known. Did BF for long periods in time live in harmony with the Native American people? Did that change with the Mayan invasion, and the soon to fallow European migration of firearm toting white people? Did the human BF equation change from trade and cooperation to one of constant conflict with the European settlers? After all, the Native American culture was under the same pressures at the same time. Armed European origin settlers were hell bent on destroying the Native Americans too. Native Americans in most cases fought back. Was the BF solution just to fade back into the woods and disappear, upon seeing the Native American solution was not working? And then there was the introduction of disease with little or no immunity within the Native American peoples. BF had to have watched as whole Native American tribes died off and perhaps made the connection of white men and disease. If you were a sentient being and watched all of this happen over several hundred years, perhaps you would avoid contact with human beings at all cost too? Is their present recluse behavior simply a manifestation of their tribal oral history? I don't blame them if it is.