All trolling and propaganda aside (and several rats have already acknowledged the terms of the "offer" to be without anything meaningful for the French despite continued claims of propaganda) the Pirates had offered the French 2 options.
Option 1:
France to give up existing ports owned in the bay France given free reign to attempt to take the Deep Water ports held by Britain without Pirate interference Pirates take remaining neutral ports in the S.America area Pirates provide no commitments against and reserve all rights to take any remaining French held ports away at any time in the future
Option 2:
Pirates take existing ports owned by the French in the bay and anywhere else they chose to
It should also be noted that there are still several factions within the Pirate nation that have their own separate interests and priorities. They were seemingly generally able to cooperate but it was clear that in the long run, nothing was likely to 'stick' in any way beneficial to the French. Also, at prime time the pirates outnumber the French easily 5:1 (note last night was perfect example where there were 4 overlapping port battles going on both with players in the battles as well as providing screening outside the battles). In addition the Pirates can captain much higher level ships than the French currently can. With a few exceptions the French are still in Cerbs/Surprise/Ren level ships for deep water port battles while the Pirates are well into 3rd Rates and Constitutions (admittedly some undercrewed but that is of little impact with current port battle mechanics).
So given two options what would you expect the French to do? Pirates would say that the French are in no position to be making any demands and there is nothing that requires the Pirates to offer any considerations since they can pretty much do what they have been doing. Given lose lose options, the French will take the lose option that give us PvP fun along the way.
Option 1: Roll over and then what? Perhaps we could take the British ports if they didn't show up. Great fun. PvTower. Then what after that? Likely still in the situation we are today but bored out of our minds.
Option 2: Put up a fight kicking and scratching any way we can given our limited numbers and limited ship composition capabilities and have a butt load of PvP along the way.
With wipes all but inevitable Option 2 really was the only choice. You can dramatize all you want about who said what and how they said it but in the end this is what it boils down to.
Of course there are those that care when they look at the map and see fewer and fewer blue dots. But at least for the French that have chosen to fight to the bitter end in the south, we realize that the game is a whole lot more fun fighting than it is looking at the mission screen.