Yeah I know, to back up the theory I think Littlefinger's motivation for what he's doing goes back to how he was screwed over because of the strict social hierarchy of Westeros. Petyr seemed to be a good kid when he was fostered with the Tullys.
The book doesn't go into detail with Petyr's pass but he's described as being a clever kid who was genuinely a good friend of Edmure and was healthily infatuated with Catelyn. Right up until he was humiliated by Brandon Stark and raped by Lysa while wounded in bed.
When he's all healed up they send him packing back home where I assumed he got to brood over how the system screwed him over in getting what he wanted. So this kid grows into a man and decides to climb up the ranks using his talents to fukk the system over like it did to him as a child.
As of right now it's the only motive that makes sense. However much a nutjob Littlefinger looks like in the books, the man's movement throughout the books looks
democratic
Very impressive that he's doing it by himself but I think Petyr's endgame if he has one, is something that's gonna be good for the common folk and bad for these feudal lords.