The commission paid out to distributors is part of total expense ratio which has a cap as per the rules of SEBI. The Total Expense Ratio cap is about 2.5% for equity funds and SEBI Has been taking measure to bring this down.
With the advent of direct plans, more investors are moving to them as the TER for direct plans is less by about 1% to 1.5%. Many investors prefer to keep the extra 40% they can make in long run by eliminating these commissions.