I agree it would be pointless studying for that long if he was forcing himself to, having lost concentration and the will to live, but he seems like someone who genuinely enjoys it and has fun doing it. And the people who say 'get a life', just because he has different interests and likes doesn't make him a retard.
OP, I'd tell your family that you doing what you truly enjoy and that it's not 'pointless', as when you get your results you'll reap the rewards and probably end up very successful careers-wise in future with your attitude.