Some contemporary scholars object that daily products are only an approximation. A business may earn a large profit while one investor has little money in the pool, or suffer a large loss while another has a large balance. Averaging the whole term may therefore not mirror the exact transaction-by-transaction use of each investor's cash.
For banking practice, the rule must also be workable in accounting and monitoring. The aim is to preserve genuine risk-sharing while using a method that can be audited and applied consistently.