Followup on "Return of the Jedi"

We know from Episode I that Tattooine doesn't have much of a government. It was too remote to be of concern to the Old Republic, and the Empire didn't have much of a presence there until they were looking for some droids. The leadership they seem to have is some sort of guild-based oligarchy run by the Hutts.

If that's the case, how responsible was it for Luke and his pals to assassinate Jabba and his entourage? I'm sure government by the Hutts wasn't always the best (they seemed partial to slavery and gambling), but it was surely better than total anarchy. Did the rebels just assume that democracy would flourish once they toppled a dictator? Did they expect to be treated as liberators? Why does this all sound so familiar?

"Mon Mothma sends her regards."