rapid westernization.
rising bar and alcohol culture.
inefficient police.
adding to the above, it has something to do with the fact that reporting rapes is not a taboo any more. women are not afraid to report rapes. now, that said, an overwhelming majority of rape incidents are still kept under wraps. but times are changing , at least in the cities.
I think, it has much to do with the political system prevalent in india. "neta ka beta" goes for a "rape n murder" spree, the henchman takes a cue and helps himself with a helpless woman. soon enough the chain increases. but in all cases there is a common factor --- inefficiency of the police force. when nobody stops u from doing a crime, effectively, u tend to do it more often , dont u ??
hence there are many factors to this shameful string of incidents.