someone forgot the basic rule: divide all 40k fluff by ten
Star Wars has the giant mono-environment worlds, not 40k so much.
So no, Earth is not one giant ball of completely totalitarian grimdark.
Someone needs to read more Andy Hoare and Dan Abnett,
and less Matt Ward and even less Matt Ralphs
Also, Peer (Administratum or Chartist) will open some doors.