The Kurds are just as bad as ISIS. They are both mercenary groups fighting for money.
The PKK wants to create a communist state and ISIS wants to create an islamic state. So take your pick. You can side with the communists, with the islamics or you can get the hell out and let them kill each other.
ISIS want a Hegemonic Theocratic Islamic State
Syrian and some Turkish Kurds want a Communist Islamic State.
The Kurds use the conflict solely for fanatical Marxist propaganda.