I'll apologize upfront, I do not know how to properly quote bits and pieces of a post so I did the best I could to make it clear.
Likelihood and education.
What if that same neighbor took a trip to Yuma, AZ, and told you that a moose crossed on the highway in front of him as he drove south toward San Luis Rio Colorado? Or if he had seen an alligator cross the road in front of him in Maine? I suspect you would either disbelieve him, or you'd think that they were animals brought there and released/escaped.
Somewhat different situation, BF are reported to be in all parts of the contiguous United State and Canada. Moose are not.
With sasquatch, we know that bipedal apes or primitive hominids existed in Earth's past, and as recently as 24,000 years ago (and, in the case of Homo floresiensis, even much more recently). Why not now (for the last of the dying population) or in the most recent past?
Bipedal apes, and hominids in the past are in no way proof or evidence that something as such may exist today. For myself, if nothing else, the fact that most evidence for a bipedal primate that could have been in NA, AKA, Giganto @ 100,000 years ago works against this idea. Why such a gap in the "records"
Homo floresiensis is believed to be smaller than modern man, proof that a hominid can be smaller than modern man is not evidence or proof that one currently exist that is 50% larger, only that variance is possible, not guaranteed.
How long for each search? (wildlife managers call those hunter-days) How many animals are available to discover? (Nobody knows). Were searches conducted when they hibernated? (Nobody knows).
A scientific search does not have to be looking for BF to find proof, so overall, there have been NUMEROUS searches that could have turned up evidence of a BF. Settlers came to this land and settled it and never came up with proof of a massive bipedal ape, but we found, beaver, fox, coyote, woodchucks etc. We do not have to "search" for something to find it. If it is out there it usually "pops" up eventually. If we are to accept "anecdotal" evidence for this creature we cannot cherry pick it, therefore, if reports show it exists in the contiguous US, given the animal observations and research done we should have....something.....
Indeed, nobody even knows the answers to the above questions I posed because the entire effort has been relegated to amateurs, no comprehensive database has been compiled on either testimony and reports, but even of search effort/search locations/ etc. The appropriate people aren't in the game. Period.
My take is the search has not been left up to amateurs. A researcher in the woods, who is set up to photograph and record observations of a Ivory billed Woodpecker (thought extinct), a wolverine (around 300 known in the lower 48), or a Grizzly Bear (around 1500 known in the lower 48) would or could observe a BF in similar habitat. Just because you look for one animal does not make you blind to others around you. I would think if a scientist had irrefutable evidence of a bipedal primate they would come forward. Ridicule or not, HD proof would stand on its own.