What You Leave Behind did touch on it a little. "Some will say that we got what we deserved." I think he's talking about the Occupation and joining the Dominion.
I don't think that reflected his own opinion, though, it was more of a sardonic comment on how others would react to the destruction of Cardassia. He's seen and experienced people's opinions on Cardassia for years, so he can certainly imagine that people probably wouldn't have much simpathy for them after the destruction of their world. I'm sure he's right, and that there were plenty of Bajorans, and others, that were happy to hear about what happened. Besides, we have seen plenty of examples of people rejoicing at mass death here on our own planet, it's not a stretch to imagine that there were people in the Trekverse that thought that Cardassia had it coming.