Despite his great reforms and his secularism, he was still a turkish nationalist first and foremost. That included suppressing the Kurdish language and setting the “purification” of Turkey as his goal. Turkey, in Atatürk’s vision, should become a nation inhabited by turkish-speaking and turkish-feeling people only. From 1931 onwards, speaking Greek, Armenian or Kurdish in public was heavily discouraged, foreign sounding first and last names were changed and so on.

Atatürk himself said:"Within the political and social unity of today’s Turkish nation, there are citizens and co-nationals who have been incited to think of themselves as Kurds, Circassians, Laz or Bosnians. " In his eyes, such identification were delusions. Maybe its a bit crude, but you could say he tried to drive the Kurd out of the Turk. In modern terms, you could see that as cultural genocide.