There is no other interpretation to this passage but that he approves of the abuse toward Vietnam veterans--cursing at them, spitting at them, calling them war criminals--and that the same behaviors need to be repeated with Iraq vets.
Beyond despicable. But Hersh is only being honest; there are a lot of people on the Left who think this way, but they know to keep their mouths shut.
Considering that he was one of the major enablers of that sort of thing, it's not surprising. He even predates "Jingus F'n Kerrey"