I Agree in a way even though I thought he was a Prick I think he had a chance of maturing into a better person. He showed some signs of possible change but he didn't have anyone to Teach him anything better. If King Robert's Letter hadn't been ignored and he became King after coming of age a maybe he would have been wiser. I think he could have changed given the right influence I mean his Queen is a Strong woman and could have showed him a better path possibly. Though I think she had other ideas. His Uncle is a good example of change after his time as a Prisoner he was broken but came out a better man. But it is how it is only shame is I imagined Sansa hitting breaking Point and running a sword through him or pushing him off something high up after missing her chance early on.
Just have to wait and see how things play out now.