If whales are ignorant of conditions on land, they probably think humans are an endangered species.

Why? It's not like there are suddenly no humans at sea. Small fishing vessels may have gone down in number but in the meantime leisure vessels and the sheer number of humans have gone up (it's massive). Humans are ⅓ of all land mammal biomass. Whale scientists are probably more puzzled by the lack of species diversity among land mammals that visit the sea.