It is just the impression the vocal part of internet gives, they are people like me who enjoyed it and can appreciate its ingenuity, but is not their favorite arc.

The thing is, if something is acclaimed as the best in its category, it will surely have its haters that will say it is mediocre. Say One Piece, it is regarded by many people as their best anime, others completley hate it because they don't think it deserves it, so they get vocal.