Humans on Mobius

[Potada]

You know what'd be kind of hilarious is if Eggman used his badniks as a way of getting through levels. Like, have him hang onto a Motobug as it zooms through a path, or have him cling to a Buzzbomber while it carries him over gaps.

[Your Vest Friend]

Thinking about it, the disparity of the lack of civilian anthros probably boils down to Japan vs Western mindset again. They're not such a big fan of anthro characters, and they especially very seldomly have whole worlds of them. Usually they will be interspersed with human or cute animals because that's more appealing and more the done thing. You can see this across most of the Japanese media; the Sonic 1 manga, the games, the OVA and the first two seasons of Sonic X. The third season had them, but that season was made for American appeal so that might be an influence on the choice to have them. The only true exception is the Sonic Shogagukan Manga, and even that mainly just has hedgehogs and not a mixed population. 

Western places, meanwhile, have anthro populations a lot because it's considered relatively popular with kids. That's why it's in every piece of Western Sonic media; All the DiC cartoons, the Archie and Fleetway comics, and now Boom. While those exposed to those will see it as natural, they really don't reflect how the games do it at all.  

Actually, unfortunately for Archie, there does seem to be a big segregation of species in the Japanese media (games included, given the Knuckles tribe and the Coconut Crew), so their idea of what amounts to total species harmony is...non-canon. At least for Anthros.