The thing with Littlefinger just felt too tidy in a way. Not enough build-up, in either a dramatic or cinematic way, to offing a character who has been so central to much of the show's conflict. Maybe it's just that the use of Bran as a huge shortcut feels like a drama-sucking vacuum, but I think they could've done more from a technical and thematic standpoint as well. Ultimately, it felt a little lazy, and I sort of feel like GRRM might've infused more irony into his death or made it more thematically compelling somehow.