Two points. 1. The varNAshrama dharma was instituted way back in ancient times in order to optimize the efficiency of the skills learned by people in various sectors. It implies that once you do a certain job repeatedly you become an expert in that and do the best job that no one else can do. But the pity is that it locked people into cells and became more or less a slavery out of which there was no escape. For example if the son of a blacksmith did not want to be a blacksmith but wanted to learn and teach scriptures he was prevented from doing so. That was the drawback. In that respect it had negative connotations when you view it from our current perspective. 2. Even when the so-called varNAsHrama dharma (which does not exist anymore) is wiped out from the books, the caste system will not go away. It is like neighborhoods, subdivisions, cities, districts etc., within a particular region. Each group tries to preserve its own characteristics. In ThamizhnADu alone there are over 4000 castes with unique identities of their own. There won't be marriage alliances within two sub-groups of the tEvar community for instance. Castes are like mini-religions. There is almost undeclared warfare among them. In my view castes cannot be abolished. When the kazhakam people promote inter-caste marriages they almost always mean alliance from a so-called "lower" caste with a "higher" caste. But they will not/cannot do anything about mayhem and murder perpetrated when two people of nearly similar castes want to marry.