Those needs will change. Requirements will come that are easy to implement efficiently in terms of SQL queries, but impossible through the abstraction. You may

Those needs will change. Requirements will come that are easy to implement efficiently in terms of SQL queries, but impossible through the abstraction. You may then be able to come up with a new interface, which requires you to change your existing code. Just like ORMs, such interfaces can be useful, but have the cost of limiting your options.