Chiranjeevi is a good actor and no doubts on that. He also has a good fan following. This does not necessarily translate on an equal basis in the political world. We have another cine icon in Amitabh Bacchan, who fared very badly on the political front.
Chiranjeevi lacks the Charisma of NT Rama Rao & also is a political novice. His own family problems are not going to be ignored fully by people and will have an impact on his political career.
The way he is welcoming disgruntled leaders from other political parties like Congress, TDP etc is not being appreciated as masses have a tendency to support loyal persons.
His Fan Clubs have also become a menace many a times,
Last, but not the least YSR has and is doing good for the masses in the last 4.5 years(though it might have been better)