Creamy layer is defined as people who have income > 2.5 Lakhs per annum (except the income from agriculture).
Definitely there are huge number of people from OBC who have less income. The Creamy layer is excluded to give them opportunuty.
It seems that the rich OBC leaders and politicians (who belong to creamy layer) want to keep the reservations only for themselves and don't want to give it to the poor and needy among OBCs.