There isn't much they can do about that other than just having westernisation. Calling Robotnik....er...Robotnik instead of Eggman. About the humans, well, its safe to assume Sonic lives on Mobius, but that mobius is also inhabited by humans. Its just a paralell to Earth rather than Earth itself
I understand all of that, I'm just trying to get across my point that very few westerners grew up with the Japanese variant of the series; I mean, nobody in this country grew up with a "Dr. Eggman." We grew up with and became decidedly attached to the western version of the story. We do not feel any similar attachment to the Japanese original; it leaves us cold.
Nothing SEGA can do about this. They can't just insert parts of the comic and TV programme canon into the game canon. Partially because the already large cast will get positively massive, and partly because each of the comics/TV programmes contain a different canon and the story would be fucked over quite badly.
And yet they played just as big a role in forming my childhood experience of Sonic as the games.