But anyway, after the Emperor's stranglehold on the galaxy, his sudden absense would leave a power vacuum, with the remnants of the Empire likely splitting into factions. (like the scattering in Dune after Leto II's demise)
Competing Imperial groups fighting amongst themselves while also trying to undermine the New Republic and prevent the 'return of the jedi' would make for a good story with multiple villains.
That's what I think, anyway