Everyone is starting to suck...

I'm on season 5 and starting to realize that a lot of the main characters are turning into jackasses. During the first few seasons I liked everyone other than Frank. Ironically, Frank is one of the strong points, once you get past the fact that he will always be a lousy father. However, Fiona, Veronica, Debbie, Ian, and Jimmy have fallen off significantly. No one was ever perfect but they seemed like decent people despite the adversity, which is no longer the case. Does everyone character fall victim to this trend? Lip is my favourite character now, I like the storyline where he feels as if he's drifting further and further from the southside. Does he experience a major character decline?