It is because of the human psychology in a society like India where VIP culture is deeply rooted as a cultural practice (or malaise) – where we all, more or less, at some point of time or regularly - face (or feel) its brunt - and the main protagonist of the movie is shown taking on such (rogue) VIP elements.
It is because such films give wing to our fantasy that craves (and at times cribs) because of the fundamentally feeble nature of human beings who have been harassed by rogue (or corrupt) elements - something that we all face – and find ourselves forced to compromise. Yes, exceptions are there but then it is not yet time for any of them to become norm in our society.
And we can see they vary according to the subsets of societies in India – like South Indian flicks portray an ‘all supercharged, superhuman like hero’ who first faces life’s troubles due to bad elements (VIPs – politicians, police, criminals with VIP sort of stature) – and then take on them with a force that dwarfs even the best bravado shown in the films made in Mumbai – because VIP culture or personality cult worship in India is most deeply ingrained in the South Indian culture.