And for me its one of the best RPG open world of all time, a real open world, not like the ones when you have to follow missions. Here you are totally free, you explore the world, do what you want, go where you want, be what you want to be. Like Skyrim.
Of course for the ones who like Assassin creed games, I undestand their frustration, but try to learn how to play this type of games, or go for a more scripted game like RED DEAD REDEMPTION 2, but never review this game like one of the games you played before with the Assassin creed franchise :)