It's obvious that it's a lefty site to begin with, so it attracts lefty readers. Lefty readers, in turn, tend to hate Israel and support Islamists. They are disgusting pigs, but those comments shouldn't be surprising.
BTW, this same Lloyd Grove used to be a DC celebrity gossip columnist for the WaPo (don't know if he's still there), so the fact that he writes for that web site should not be surprising, either. Did you notice that Grove didn't bother to interview a single Jewish Republican for his story?
24/7/365 Israel-bashing has degraded popular support for the Jewish State, and those who support her. Add in the ever-present dusting of Jew-hatred in the culture, and the current intellectual climate shouldn't be a surprise.