I don't see how someone can be pro-Jewish and say that, especially to have that attitude toward their own bretheren.
Assuming you refer to Ron's post, it is clear to me that it is because he views them as traitors. There is not a more dangerous ennemy than a traitor or an ennemy within. Jews who support Muslim Nazis are traitors to the Jews - and a danger to humanity in general...
Here, we have Jews who choose to live in a country that committed a genocide against the Jewish people and did not subsequently try to make up for its crimes in any significant manner - on the contrary, that country watched in indifference (or maybe delight) as Israel was on the brink of being destroyed by the Arabs several times. That is already bad enough on the part of these Jews (although I wouldn't wish death to them for that reason alone).
But their case is seriously compounded by the fact that, today, they support Muslims who want to exterminate the Jews ! Can't they justifiably be called "Judenrat pigs", even though the expression is provocative ? If I had to choose between the expressions "my own bretheren" and "Judenrat pigs" to qualify them, I would take the latter without hesitation.
Anyone who supports Muslim Nazis deserves to receive the treatment that Muslim Nazis inflict on "infidels". There is free will in this world and if we choose evil, we must bear the consequences of our decisions.