In retrospect, I liked his character: He's a weakling and they've purposely designed him to be one. But in the end, the decision he took made him truly evil. They clearly designed him to grow more and more badass over the trilogy and as I liked the movie I'll give them the benefit of the doubt. He has room to grow as a character and a villain.
God, I can't believe Episode VIII is scheduled for May 2017... it's way too long :/