Why is the item history in the Demand Plan view different than the Requirement Plan view?

The S&OP Demand Plan history is always shown by its Ship Date and Ship Quantity regardless if the forecast is based on the due date and due quantity.

Since the Requirement Plan always matches the forecast basis, if the due date and due quantity option is enabled in system settings, the history of the requirement plan view will likely differ from the demand plan view if the actual shipments vary from the customers requested shipment requirements.