How is it screwing a customer when one purchases a discounted ticket which may only be changed for a fee and is then permitted to change it without a fee?
The entire concept of SDC cannibalizes the refundable/changeable full fare brand. Maybe waive the fare difference for same day changes, but why drop the change fee from $200 to $0?
The guy who has a meeting running late will gladly pay the $200 to catch a later flight because he has to. People doing it for pure convenience will have to make a value judgment.