Eh, that’s fair, but they definitely got sick of the show after they passed the books and put an artificial cap on it so they could move on to other things instead of letting the story dictate the length of the show, whether that meant handing over the reigns to someone else or sticking it out as long as it took.
Well I still doubt your premise (re: the artificial cap because they just wanted to move on, not the artificial cap itself) is true but either way we can agree that the last two seasons are rushed and messy as hell.