There's some genuinely weird shit unexplained, I'll give you that. Unlike Bigfoot, where you can look at a map of the historical range of bears and see it exactly matches where all the Bigfoot sightings are.
People claim to see Bigfoot creatures in the Mississippi Delta and Florida... Even Scotland. None of these are much noted for their bears.
I dunno. I think the fact that these sightings are always from sleep deprived individuals describing things at the far end of their range of detection (whether that's 5 miles away with the Mk 1 eyeball or 500 miles away with classified superradar) suggests a pretty clear pattern.