Peace trumps some random pieces of land.
And in the 24th century, where your "home" is just doesn't really matter. The UFP is a utopia where all your basic needs are provided for and you can work as whatever you want.
It's not like now where relocation might mean having to find a new job, a new house, etc.
The Maquis "cause" was just silly.
Wasn't the whole Marquis/Cardassian conflict none of the Federation's business though. I mean last I hear on the subject they weren't federation citizens any more.
Plus it was a crappy treaty anyway.