I would use the word "interesting" as opposed to great when talking about serious flaws.
Some of the most vile characters can be the most popular. It's so ironic, like a guilty pleasure.
Dukat was a rapist and sexual exploiter- no way around that one. Those women were rounded up and brought to him and his officers. It was made clear they were to show the proper "respect" or else.
Dukat was a very immoral person, he just covered over his actions by acting polite and genial.
The ones doing the exploiting, like Dukat, usually live in their own reality, totally oblivious to how immoral their actions are.
Hell, Dukat thought he deserved a statue in his honor, and didn't know why the Bajorans didn't build him one.