And I'm sorry, but when it comes to the Mass Effect universe, I don't give a crap about Earth.
Except the plot of the Mass Effect games have always revolved around humanity.
Mass Effect 1: Saren spend most of his time attacking human colonies, with most of the guess for why he's interested in Reapers being that he wants to wipe out humans, you don't find out that Saren is a puppet until Virmir
Mass Effect 2: The Collectors are targeting human colonies.
Really when it comes down to the Mass Effect games the plot boils down to humans are screwed The Council doesn't want to do anything about it, so its up to Shepard to save the day, so really why expect them to change that just for the last game.