According to the Bhagavad-Gita, the Aryan family system has broken down in India over 3000 years ago in Krishna's time. Therefore today, 3000 years later, the social system of natural aptitude has degenerated into the caste system, which only resembles it in form.

So with the modernization and more liberalized and the changes that have been made to fight against caste discrimination, why is there such thing as outcastes still?
One reason might be that the whole ethical code of belief that the Indians uphold is very fatalistic and idealistic. This applies in the dharma and moksha beliefs where the lower castes have kept quiet and accepted the discriminating treatment as the life God has set for them.
Even if the lower castes change their beliefs about being resigned to the fate of their lives and do something about it, it is important to bear in mind that it is almost impossible for one to change their castes. An Untouchable will always be an Untouchable.

There is a backfiring effect to the protected actions administered for the scheduled castes. The affirmative action by the government serves to further perpetuate the discrimination problem because the lower castes are highlighted and made different again compared to the rest of the castes. The special treatments of being on the government"s list or schedule, academic entries, voting rights, only make the discrimination glaring, adding onto the existing stigma.