Oh I've experienced it John, but as I intimated in my reply, looking Asian shouldn't present a problem for a visitor to Istanbul.
I also know many Kurds and know of some of the problems that they face in Turkey. They suffer 'racism' just as badly as as those that suffer 'cityism' because they're from Izmir, Konya, Fethiye etc. For instance we were always very surprised at how much people from Kaya despise people from Fethiye. Now whether or not that's racism, villageism or just plain mis-paced hatred brought about by jealousy, I haven't got a clue.