I am fairly new to being a DM. I recently wrapped up Kingmaker: The Stolen Lands, for Pathfinder, with my group, one new player and a veteran. The veteran is playing a tribal native ranger from the surrounding lands. Upon completion of The Stolen Lands, he decides that his character hates the newcomers and wants nothing to do with the nation building, which is a major part of the campaign. I tried to have a couple of NPCs show that not all the settlers are weak, murderous, blights upon the land (his words), but he states that this is not enough.
Should I end it?
If not, what should I do?