Christian missioners: cultural invasion on national identities and spiritualities?

Christianity has been present in India ever since the time of St. Thomas, the apostle. From then, conversions from other faiths into Christianity have been carried out. India is the land of Hinduism. Hinduism is not a religion in the traditional sense of the word in that it does not have a founder or any hard and fast rules; rather it is a culture or a way of life.
The caste system is the bane of Hinduism. There is a huge socioeconomic disparity between the higher and lower castes under the caste system in India. The lower castes have been discriminated against and oppressed for centuries. The privileged castes did not want the lower castes to climb the social ladder. Left with no other choice, the lower castes converted to other religions to gain whatever respect possible. The new religion gave them a higher social status.
The Christian missionaries under the pretext of serving the poor are converting innocent and ignorant people to Christianity luring them with jobs and other monetary benefits. However, conversion to Christianity cannot be considered as cultural invasion, rather it is the failure of Hinduism because of its caste system.
India is democratic and its citizens are free to follow any religion of their choice. If people convert to the Christian way through their own will, there is nothing wrong. But, using coercion and inducements to convert people is against the very spirit of religion.