From a Cardassian point of view, Dukat was a pretty lousy prefect and a disaster as head of state.
- Failed to win over any hearts and minds of Bajorans during the occupation, and his harsh methods also failed to get the resistance under control
- Lots of Cardassians had Bajoran mistresses, but they don't parade the results of those unions down the streets of their capital. A good father's job, from the Cardassian point of view, is taking care of his family. His legitimate family, not the child of an affair with some Bajoran. His actions greatly hurt his wife and their children. He wouldn't have even had to kill Ziyal, he could have just not gone on Kira's quest to find the Ravinok. Or not mentioned her and allowed her to be cared for as an unknown orphan.
- Speaking of the Ravinok, she was a Cardassian ship. Wasn't it Dukat's job to make sure there was a thorough investigation into what became of her? If Kira could find out just by calling in a few favors, Dukat certainly wasn't trying very hard since he failed with all the resources of Cardassia available to him.
- The alliance with the Dominion that he engineered, umm, didn't work out so well. Even if the Dominion had somehow won the war, it's clear Cardassia would have lost. That was completely predictable to anyone but Dukat. How many Dominion worlds in the Gamma Quadrant have any independence? Umm, none.
- When returned to command of the station under the Dominion, his superiors told him very forcefully to get the mine field taken down as soon as possible. He worked on it some, but made other things his priority, strutting about in front of Kira and competing with Weyoun for the Founder's attention like a preschooler.