You don't hate Paul Dano, you hate his character, and that's because he did such a great job. If you don't think Paul Dano can act, then you're not familiar with his other films. Go watch a few others, then come back to TWBB. You'll see why so many people like him.

The only part I didn't like in There Will Be Blood was Paul Dano playing two brothers, but setting it up so you can't say that the main character isn't pretending to be the brother that doesn't exist. Like, they should've been more explicit about there being two brothers. That make me question the entire relationship between him and Daniel Day Lewis' character.