Negotiations of the EU with neighboring countries are not on an equal footing, or in a spirit of cooperation around objectives commonly defined. Those with Turkey are no exception.
Turkey made for many years the choice to facilitate access to its territory for a short stay: Nationals of most countries of the world can come here without a visa. The European Union wants to make Turkey a buffer state slowing the arrival on its soil of “migrants”, mainly potential refugees. The currency exchange is the possibility for Turkish nationals to enter the European territory being exempt from short-stay visa. To achieve this, Turkey must submit at roadmap asking a series of conditions: the readmission of its own citizens and citizens of other countries who have transited through its territory if they are expelled from the European Union; the security of identity documents; border surveillance; visa policy; legislation on asylum; policy vis-à-vis irregular immigration; measures regarding security and judicial cooperation; and final conditions for fundamental rights (in terms of minority rights in question the rights of Roma in Turkey – and we would like them to be respected in the European Union – but not rights of Kurds, who are not mentioned).
You can download the roadmap here (in English).