This has been said before on here, but the main reason here is because in the West (particularly the US and Germany) there was a large group among the general populace supporting the genocide in Gaza, but in the West there is no large group supporting the massacre in Iran. The latter is an extremely fringe position to hold on the level of flat-earthers. People either don't care or are against it. When there's such a consensus, there's less controversy, less to talk about.