Most likely many influencing them are in bed with big pharma.
Having the movement start with states rights is good for the little guy. It keeps the big sharks at bay. Allows the little guy to grow into the market and be more competitive when the flood gates open. We are now seeing where it's becoming more and more difficult for any average Joe to start up. Any businesses currently operating have a leg up. Part of this is due to the continued stance by the federal government that mj is a schedule 1 drug, while states move to legalize. I also believe this is partly by design. As long as congress upholds the will of their local constituents, and the mj grass roots movement continues forward, mj will eventually become legal at the federal level.