Why are South Indian films, not Hindi films, called pan-India: Nani

Speaking about the term “pan-India” used for films, Telugu actor Nani said, "Don’t call my film pan-Indian...because I ideally don’t want any film to be called pan-Indian.” "If a Hindi film becomes a big success in...Telugu, Tamil...or Malayalam versions, it isn’t called pan-India,” Nani added. “Why is it introduced for South Indian films? Why not for Hindi films?” he stated.