It's probably my biggest gripe with season 7. Dukat used to be a great multi-dimensional character: when in control, he displayed his smug arrogance, but his obsession with being regarded (or even just excused) for what he did during the occupation--especially by the Bajorans themselves--revealed a much deeper personality that's haunted by doubt or maybe even guilt. He had moments where you could actually feel for him, he had moments that made you think there's hope for him, but then when pressed he revealed just how psychopathic he is. Very multi-faceted, with several layers on top of each other, great stuff.
In the end of S7, he was basically just a tool of the Pah-wraiths and his final encounter with Sisko was just "I won, you lost, bwa ha ha" and that was pretty much it. As if that was all he ever cared about. This character deserved some much better resolution in my opinion.
Winn too, I mean she was pretty evil most of the time, but occasionally she was deeper than that too. I actually felt bad for her when she desperately realised she was serving the Pah-wraiths while thinking she was serving the Prophets. But shortly after that, she just goes "screw the Prophets, I sell my soul to Satan now", murders that guy and whatnot. No further attempt to do anything meaningful with that character.
And that final stuff in the fire caves is so off, it's more Lord of the Rings than Star Trek.
Then there's the question about Bajor's future and politics. The matter of Bajor joining the Federation is just dropped without further mention. Bajor politics which had been pretty important in earlier seasons are completely nonexistent. Bajor seems to have only three people, Dukat, Winn, and the guy she murders.
Altogether I found this storyline pretty disappointing. DS9 used to do better than that.