I don't know if it is controversial but I sided with the Marquis. The Federation left it's citizens high and dry by signing a treaty with Cardassia and ceding to them worlds settled by Federation citizens.
i think the biggest issue is Cardassia didn't seem like that big of a threat to the Federation and the Federation just seemed like wimps for signing the peace treaty and ceding worlds. Maybe if the Cardassians seemed like a bigger military threat the compromise would make more sense.
The Federation should have not handed those worlds over to Cardassia and stopped doing so much to appease the cardassiansin order to keep the peace.
I agree with you on this, the treatment of the colonists along the cardassian border was abysmal. The expectation that the colonists would give up their homes and upend their lives for the greater good showed how out of touch the Federation was with it's own people.