What do you suggest ?
A war ?.... and kicking out the Turkish people from North Cyprus, or make a Palestina of them ?
You are too impatient
as usually 
(like playing chess and moving your queen, knights, bishops all over, just spilling moves and ignoring that the humble pawns are the most important chess pieces for your positional play structure)
At the moment East Europe joined the EU, the economical use (as cheap labor country within the supply chains of the EU) of Turkey diminished greatly for the EU.
At the moment China and the Asian tigers grew massively their cheap garment, footwear, TVs, etc,etc... completed low priced goods to increase the buying power of (low income) consumers in the EU, the importance of Turkey for these goods diminished greatly.
Turkey as a whole, in its behaviour, did not and does understand that change in position from external processes.
Keeping up presence in North Cyprus will be expensive... supporting North Cyprus economy will be expensive.
As said: when North Cyprus people decide themselves to want to join Cyprus because "everything" is better (except that flag)... the situation will solve itself.
For now it is only that fossil revenue.