"While I seriously doubt that Turkey can genuinely meet the financial criteria..."
That shouldn't present a problem. If Germany applied to join the EU now it, too, wouldn't meet the financial criteria required for membership. Germany has run a current account surplus of around 8% for donkeys' years, falling from that level only briefly around the time of reunification and the 2008 financial crisis. The EU target figure is 3% and with the rest of the eurozone running a surplus of around 2%, Germany (via its membership of the euro and that currency being designed principally for the German economy) is largely responsible for stagnation in the eurozone and for the financial problems faced by the peripheral eurozone members. Other countries wishing to join the EU (and who would have to adopt the euro) would not be allowed to join whilst they save too much and buy too little (the cause of the surplus). But I would wager that Germany would.