It is about how the Ottomans actually allowed for a Kurdish millet (even though they were fellow Muslims) in order to allow for space for cultural and ethnic identity and reduce tension:
For the record – the Kurds were one of the most loyal Ottoman communities in the entire empire. And their nationalism only started once Turkish nationalism kicked off. This gives us insight as to how and why this “supra-ethnic” bond was achieved.
The article can be read here