How Spike seems to have jumped back to his Season 2 character, thinking he has to act like other dragons, seemingly having a mysterious case of amnesia on Dragon Quest
and Gauntlet of Fire,
how so many characters act incredibly out-of-character, as if they've been replaced by changelings, how Starlight Glimmer suddenly has parents out of the blue, and they mollycoddle her like a five-year-old even though she is an ex-supervillain-turned-Equestria-savior. Also, the school. It's been put across many times in the show that friendship cannot be taught in a classroom, and the only way to learn it is to go out and experience it for yourself.
In fact, just read this essay I posted, it'll be quicker than writing it all down here.Why I Hate MLP Season 8