Where he said something like 'He would burn down the whole kingdom just to sit on a throne on it's ashes'.

This scenes sums it up:

https://www.youtube.com/watch?v=tejsD8QdlN8

He's always had power + wealth in the series...he's just trying to get nobility and a house and ultimately the big prize the throne.

We can argue that is a poisoned pill, but you gotta figure Littlefinger thinks he can run shit much better and control all the pieces.