Originally Posted by The Joker
Forgive me for misinterpreting your meaning, but since the topic was what made Bruce quit on life I assumed you were offering extra reasons for it.
You are forgiven.
But I certainly think part of why Bruce was depressed was the weight of the guilt from all the escalation, mayhem, death, etc. that he feels he caused from being Batman and provoking criminals.
It was too much for him, yet at the same time not being Batman meant that Bruce didn't have anything really driving him. The guilt became heavier and heavier. He was lonely. He felt like a failure. Eventually he hit absolute rock bottom.
This is what makes me appreciate Nolan's trilogy so much. The focus was always on Bruce's personal, emotional journey. That's one of the primary reasons why I love TDKR so much. It hit all the right emotional notes for me.