Both sides messed up IMO.
Some of the Maquis had some strange ideas about home- colonize a planet on the border with Cardassia, even though they were warned not to do it.
Just taking a look at what Cardassian military can be like should have made that decision easy.
The Federation is prosperous- they have plenty of planets to choose from.
At the same time, the Federation bent over backwards to please the Cardassians, even after all their plots and schemes were uncovered.
The truth is though, that any group of people who are stubborn enough to move onto a planet right on a disputed
border with a hostile power with a reputation for brutality, despite being warned--
-- is going to the be the same type to form a terrorist/resistance group and fight unto every one of them is wiped out.