Monthly income plan is not necessarily best for every one. This depends on individual need. Rate of return, safety of investment and liquidity viz. getting cash when necessary are the main considerations. Monthly, quarterly or half yearly returns do not matter as such.
Monthly Income plan is best for those who have a lump sum amount with them and need regular income. Fixed deposit is good for those who do not need regular income. Thus the retired senior citizens will prefer monthly income plan. A young person will prefer fixed deposit.