While I agree that the chant might be a bit crass, I think it's his right to say it. He's saying the army and what it does is shit, and should suffer. I find it very discouraging that such a statement is called antisemitic. The way you frame it is exactly how I see it, it's death to the abusers, to the killers, the soldiers. It's about the violence committed by the army.

It would be as if The Andrew Sisters at a gig in 1943 shouted "Death to the wehrmacht", and people reacted with "well that's quite anti-german innit?". No it's not, it's anti Wehrmacht, just like his chant has something specifically to do with the IDF, not with Israelis.