It is part of the dehumanization of the native population. “They were all primitive and savage and now look how we’ve civilized the place.” To propagate the myth of a land without a people, just the same as the Native American or the Native Australian populations who have been conveniently ignored so you could displace and/or kill them.
I never realized it but you’re right that it seems extremely reminiscent of the myth of the untouched wilderness of North America or Australia. It’s like “Wow! It’s so empty and ready for settling!” when there’s whole populations and societies who have lived there for thousands of years and carefully cultivated the environment. Both still have to go through a long, struggling genocide to settle the area so you think that would dispel the myth right there, but for some reason it still persists for all 3 areas, even today.
