The basic problem is that devoid of Marxism-Leninism or Islamist ideology, there as many Kurdistans as there are Kurds. There is no unifying notion of what a Kurdistan is outside of these ideologies.
What goes on, and why the Turks are so recalcitrant in all this is that the PKK goes into a Turkish town, killing everyone remotely related to the government, like the teachers, doctors, and their families, the dogcatcher and all the dogs, or some indoctrinated homicidal-suicidal psychopath walks into a crowded department store with an incindiery bomb wrapped around him and sets it off. Turkey had to deal with the equivalent of 9/11 several times a year for more than ten years. When they responded they were vilified as monsters here in the US and in Europe.
The US and Europe have been extremely loath to support Turkey's fight with the PKK, allowing their political organs unimpeded and unconfronted access to the media and academia.
This is how the last Gulf War turned out for the Turks, with the added bonus of a collapsed economy due to her boycott of Iraq, a major trading partner, and Washington failed to deliver promised economic relief. The First Gulf War, followed up by the Clinton administration, was a prolonged nightmare for Turkey. Her security was compromised, not enhanced, by our lack of concern. Turks have learned a hard lesson in how no good deed goes unpunished.
This time they wanted the command and control of their own troops in Northern Iraq, to which Washington responded with a flat no. Erdogan and his idiots running the Turkish government were unable to generate a clear Parliamentary majority for the stationing of US troops on the Turkish-Iraqi frontier, continued to coyly dither any remaining good will from Washington away, and so now Turkey is included out of the loop so far as the New Iraq is concerned, but Washington expects them to be placated with assurances that there will be no Kurdistan.
All in all, a fine mess for everyone, and all parties concerned bearing responsibility, for reasons mostly related to ignorance and incompetence, which produced a profound lack of trust.
In contrast, we could have had a Turkish armored division stomping the terra in Northern Iraq, finally burning out the hornets' nests, causing problems by the score for the enemy.