A who’s who of Cardassian officers and Bajoran collaborators (Darhe’el, for example) were persona non grata at best, and arrested to face charges of war crimes at best. I can imagine that, if there were no specific incidents which could be linked to Gul Dukat, perhaps he and other Cardassian officials would be tolerated… But as he was the head of the occupation, I’m not sure this makes sense.
Is the best explanation that this is merely a matter of convenience to normalize relations between Bajoran and Cardassia, or is there a plausible justification for his semi-frequent visits to DS9 and/or Bajoran in the early seasons? What real historical examples are analogous to his relationship with the Bajoran (provisional) government?
I could think a good scenario where small fleet of Kazon (or other pirate-like enemies) pursue Voyager far beyond where they first encountered, nipping at their heels and causing trouble sporadically… but yeah there’s no reason Voyager should have been always in the heart of Kazon territory.
Add to that the fact that they weren’t a very compelling bad guy in the first place and, well, we get what we got.