its vote bank politics for the following reasons its really easy to please minority imposing the concept of minority in to them(what every political party is doing) The majority in every community never stand organised and togather so every political party try to influance at least one minority
Else BJP will be the sole winner after the 1992 Ayodya issue. (leave behind the 80% vote if they could assure 40% of the hindu vote)
so every political party divide the population based on religion cast for their convenient. if people does not divide they plan some riots(Gujrat, Kerala, and many more) and fill hatred in to common mans mind and then drink their blood.
almost every riots or communal tension was created by politicians for their benefits. if you dont believe so tell me a single one in the resent past that happened for any other reason.