My impression is that the original setting allowed plenty of latitude for people to find their niche in any of the empires. Of course, these are vast societies - unimaginably large by today's standards - and obviously you're going to find the whole spectrum of human behaviour and morality in all of them. I think most people understood this from the outset.
OK, the Amarrians were always the most decayed apple in the barrel with the slavery aspect, but it was easy to assume that most people were fairly pragmatic and ordinary despite that. Besides, it's quite easy to reconcile the slavery angle with a normal society because in our own history, the absence of slavery is the anomaly. Our modern western democracies were modelled on the Graeco-Roman societies of antiquity: societies that depended upon slave labour. Most European kingdoms had some kind of slavery present after the collapse of the Roman Empire that persisted through the middle ages as serfdom. Slavery still existed in some nations until comparatively recent times. It's what, 150 years since the US abolished slavery?
In short, it isn't hard for us to imagine a monolithic religious society founded upon slavery. We might not think that's a Good Thing, but we can easily accept it as feasible and not suppose that all of its trillions of inhabitants are the moustache-twirling villains that Lallara mentioned.
The trouble is that four empires that are morally grey and ambiguous make it very hard to tell simplistic stories about baddies and goodies. You reduce trillions of people to a single stereotype and look to elaborate conspiracies for your complicated plot devices. A few hundred pages later, you have left the original setting a much poorer place.