Turkey simply isn't going to follow the EU by-laws on democracy.
geopolitics
_A study of the influence of such factors as geography, economics, and demography on the politics and especially the foreign policy of a state_
in fairness, these rules are being skirted within the EU constantly. Bypassing checks and balances and overall centralization of power seems to be a theme for many nations. Admitting Turkey without both fixing the EU's internal rules/structure to better allow for reform and compliance to values as well as Turkey getting in line with EU standards on issues like human rights, judicial independence, freedom of expression, etc.
I'm not sure if it will be in my life but I expect all these issues to eventually be rectified and integration to happen.
SS: In a new move of shifting goal posts, Turkish president Erdogan has linked Swedish accession with renewed talks if Turkish EU membership. This is expected to be aimed at domestic audiences as Sweden is already covered by mutual defense treaties with neighbors and is closely aligned with NATO members. It is not expected to integrate Turkey into the EU anytime soon as it would disturb the balance of power within the alliance. Rapid EU expansion resulting in a debt crisis and political instability within the Union have also made members more wary of bringing in new members without heavy vetting.