Well then, the Kurds do not sound like very good Muslims, do they?
I think they realized a long time ago that other Muslims do not give a squat that Kurds are Muslims, and will just as ruthlessly exterminate them as they would any other infidel.
However, by being Muslim themselves, it turns the aggression of other Muslims from active (like they have for Jews and Christians), to passive. That is, other Muslims need to have some other reason, no matter how petty, to slaughter Kurds; they are not under any religious obligation to do so.
There have been times when the Kurds were just about wiped out, along with several other groups in the region, and were saved only because their oppressors lost interest.
In any event, I do not blame the Kurds for wanting to make alliances with powerful friends, even Israel.