He acknowledged that charity-as-is is currently failing, largely thanks to poor leadership by people like him?
He acknowledged that he dislikes wealthy people as an almost fundamental belief (as opposed to just having it be an undertone of the article)?
No, he didn't. And you know, when you take time to write a series of articles encouraging people to "Dial Down our Enthusiasm over the Billionare Giving Pledge" - that deserves being called a jerk. He could be building the world, doing things, but no - he's slinging mud. That qualifies as jerk behavior.
Edit: He also doesn't mention the conflict of interest here - he's currently a philanthropy director who stands to lose a lot of influence, power, and prestige as a result of this. He used to be a top dog in philanthropy, and now he's slinging mud at people who are doing different, probably more effective things than him.