Evidently you haven't had many dealings with academic leftists.
I don't know many people like that. The peacenik kids I knew pretty much grew out of it. Obnoxious liberal teachers were obnoxious in so many ways that politics certainly wasn't at the root of their troubles. A religious or political conversion might have made them better, but more likely it would just have given them new targets for their anger.
I don't know much about Michael Lerner and the others attacked in the article, but I doubt they want a "Second Holocaust." People who write that way aren't making a rational argument. They're looking for a lemming-like emotional response. What the author says may be true or may not, but he hasn't proven his case. Therefore, I don't encourage his way of argument.