The show's setting is so pompuous and jazzed up, there would always be a thin line between quality and cringe. So maybe it's a blessing in disguise (TM) that they end it on their terms, because there is no middle ground: the moment they'd try to "artifically" milk more seasons out of the story it would turn south. Last season's final was also a natural setup for the show's final act, it may have been hard to go for yet another lap or more after that - I think we all know those shows, that end up losing themselves, stacking painful "twists" and escalations upon each other to somehow stretch things out.