Originall, Kurds were a social rather than an ethnic group. They were nomadic or semi-nomadic Persians and speak a language closely related to Persian.

While they had a brief period of being self-ruled (or at least being in a loose confederacy of self-ruling but cooperating tribes) during the time of the Qara Qoyunlu (Black Sheep Turks) in the 1400s, they have since always been divided between other states, most commonly the Ottoman Empire and the various incarnations of the Persian Empire.

The Entente acquired their own populations of Kurds in French Syria and British-dominated Iraq - to create an independent Kurdish state would give themselves problems with their own Kurdish populations, who would want to break free and join this Kurdish state.

There were thus no advantage for the Entente to create a Kurdish state, and several disadvantages. The Kurds had no powerful speaker for them at the peace negotiations either, and thus ended up split up again.