Are you telling me that there was no opposition when Hindu laws were reformed. It was Sangh and many Hindutva leaders who fought tooth and nail against the reformation. Here are a few excerpts for you
"These bills aroused strong opposition from the Hindu nationalists. In Parliament N.C. Chatterjee, the Hindu Mahasabha leader, and S.P. Mokerjee protested vehemently against what they took to be a threat to file stability and integrity of traditional forms of marriage and the family in Hindu society.
Source:
Nehru And The Hindu Code Bill - Outlook India
So you see, furore was created even then.
So is the reservation given to Hindu backwards not based on religion? Why should a Hindu backward get reservation but not a muslim/christian backward?