David did a good job claiming credit for creating Occupy, but he was actually just one of many activists who initially heard the idea from Adbusters. In fact, I am the one who first told David about the idea and asked him to attend an early organizing meeting.
Unfortunately, that was the game he played, he let people believe so he could benefit. Others reported the same behavior. In any case, he did many good things and wrote many important books. Just important not to propagate incorrect myths.