Ottoman empire is a past and its just another empire like the Roman and Greek empire which flourished for a particular period and dried away just like most of the empires. Turks should concentrate on the present and this remembrance of Ottoman glory wont benefit their present circumstamce.
Also the fun fact is that the Caliphate was never able to control the entire muslim community. There were numerous sovereign muslim kingdoms in Spain, Central Asia and Africa which never gave two hoots to what the Caliphate has to say. They ruled as per their wish and maintained alliance with whomever they found beneficial. It is a farse that the Caliphate united the muslim world.