Religious Reforms in Hinduism

Can a religion's basic belief's be changed. In the 3000 years old history of Hinduism many people have tried to question its core beliefs and convey to its followers a new way of living life without those. More famously Gautam Buddha, Mahavir tried it and the former with quiet a bit of success. While many countries (whose pre-historic religious beliefs are unknown) accepted Buddhism and it flourished and stayed forever. In India thousands of Buddhists shrines were reconverted to Hindu temples and Buddhism was slowly sidelined while Jainism could succeed only in very small patches across the nation. In modern times, these beliefs were questioned by the founders of various Samaj - notably Raja Ram Mohan Roy with his Brahmo Samaj, Swami Dayananda Saraswati with his Arya Samaj and the Prarthana Samaj in Maharashtra. These samaj really died with their founders and any followers after were only nominal.
So Is reforming a religion so difficult?
Changing a religion is difficult by preaching, which these movements have tried. Albeit its unfortunate, but history has shown that change can be achieved by sword though. The success of Islam in the subcontinent has proved this. (Yes, I would say Islam has succedded in India although some would disagree saying India is still a predominantly Hindu country. Just add 16 crore Pakistanis, 14 crore Bangladeshis and 15 crore Muslims in India. The sum is 45 crores, while Hindus in India amount to 90 crores which means Islam has succedded in 33% of the people to leave its Hindu beliefs).
B R Ambedkar questioned, debated, requested to change, and finally out of frustration decided to abandon these beliefs and accept a new way of life. 5 lakh of his followers converted with him. But inspite of being a God for crores of downtrodden people in India, those who swear by his values, those who go wild at the slightest of disrespect towards him - how many of them have really accepted the religious path that he showed. Many of those who vote for parties following his isms, have preferred to still be in the same religion that he opposed.
Will Hinduism ever change then?
Change has occured though - like there are hardly any Satis today. There's no untouchability although people still follow strict caste system- like not marrying outside. Dowry is still rampant and absolutely unashamed about- what with many software engineers bragging about getting two to three million rupees. Many young generation Hindu Indians are ready to marry intercaste but dont actually do so for not going against their parents wishes. This generation will certainly not object to their daughters and sons marrying any good person from the other caste. Caste system may go or atleast the boundaries may blur but it would take an entire generation to phase out (the current parents) to realise that.