The argument is quite simple. If I decided to criticize Israel on this forum, but instead of saying, "Israel is wrong, and shouldn't do this...", I'd say "the Jews are wrong, and shouldn't do this...", I would be a classic anti-semite, and everyone would quickly point it out. You're doing the same thing with Palestinians/Iranians, transforming them into the One Big Boogeyman Muslim Horde, which is very short-sighted : it conveniently omits to mention the existence of Arab Christians, Persian Christians, Persian Jews; it brushes over the very real differences between Muslim countries (Indonesia is not at all similar to Morocco, for example), and between Arab countries (Saudis are very different from Algerians, another example). Your rhetoric was typically racist, though maybe you don't even realize it, which would be unfortunate but also unsurprising, considering how widespread anti-islamic sentiment has become.