Humans evolved on Earth, they are adapted to its environment. It will naturally seem that Earth was made for them, when in fact they were made (adapted) for the Earth.
Anyway, not all of Earth is suitable for humans. The seas are not suitable, underground is not suitable, only the land surface is. And some land is too cold, some is too hot. Like other species, humans occupy the niche they are evolved for.
Finally, even though humans evolved on Earth and are fit to live in it, it is not true to say that Earth is a particularly pleasant place to be. Certainly it could be much better. God might have created a world without mosquitoes or other biting insects, without diseases and parasites, with more edible plants, a milder climate, and fewer predators. The fact that all of these hazards exist, that life is in fact a "Darwinian struggle" rather than a Garden of Eden, shows that no benevolent God created Earth - rather Earth evolved species in competition with one another, of which humans are one.
Thats quite a tale..
Science fiction must be very logical...
Reality need not be so logical.. nothing to prove..