In the olden days you could fly on someone else's ticket. I know I flew on my brother's ticket a couple of times when he couldn't go somewhere. It was a quick turnaround trip. I think couples unable to use their weekend vacation tickets would give them to friends who could use them. Then came 9-11, which changed everything.

These tickets need to be made transferable. For many they may not get their money back, but if you can resell the ticket you ought to be allowed to do so.