Given that the initial funding of ISIS was probably a joint project involving the Turkish wing of the Moslem Brotherhood (including Erdogan) and some elements of the House of Saud who think their king is too "liberal", I doubt if asking Erdogan to play nice and not help ISIS will produce a useful result. And while Ataturk believed that Turkey had to abandon islam in order to become part of the modern world, he was quite willing to use islamist sentiments to encourage Turks to try to wipe out Greeks and Armenians in Turkey. So if Ataturk was around today, he'd probably admire the skill with which Erdogan is using ISIS as a hammer against the Kurds, even if he didn't like the fact that Erdogan is a fanatical muslim.