This is the standard for most "cream" pies (like Chocolate or Banana Cream). The debate here is usually over stabilized whipped cream versus fresh, which can weep over time.
Traditionalists believe a savory, flaky lard or butter crust provides the necessary contrast to the sweet filling.
Since the filling isn't baked in the crust, the crust must be fully "blind baked" (baked empty with weights) to prevent it from becoming soggy.