Well, your critique for double standard is fully just. But, although I support the notion of seperating political and sportive matters, the issue with both cases is different. The Islamic Republic is an internal problem for the Iranian people and therefore nobody no cause for concern for outsiders. As far as their anti-Israel comments go, they have done that for the past 27 years, so why all the commotion now?! The reason is political again, because the West is looking for any means to pressurize Iran at this moment. But as the promoters of freedom of opinion, they should not be looking to punish a country for the opinion of its retarded leader. And their nuclear ambitions or ay other issue is a matter of the Iranian people , not that of foreigners.
However, the case of Israel is completely different. It isn't an internal issue, since it concerns two nations and the one in power, Israel, is practicing apartheid and oppressing another nation. Therefore, refusing to acknowledge a country which practices apartheid by not playing against them is acceptable to me, but excluding a country from competition because you think they shouldn't go nuclear is just another thing. Namely, the former act is meant to condemn apartheid and recognize the rights of the oppressed nation, while the latter case is just meant for the West to force their will on others.
May the West exclude Irahn from the World Cup, it would be their most amateuristic mistake ever, since they would exactly realise what the Islamic Republic wants: a closer connection with the people and the false illusion based on emotion among Iranians that the government is a nationalistic one!