If you read my post properly you would see I mentioned this being at the END of the passengers' Journey!
At the end of their journey, why would they travel further on it?
I've asked gateline staff to let me retain my ticket for expenses purposes a fair few times (since the barrier would eat it)
Ah OK.
In my opinion ticket barriers should return all tickets but have a facility to print a code in small print on them showing which barriers they've been inserted in to and when e.g. EXIT EUS 04/03/2014 11:54
Have you never heard of people trying to re-use "open return" tickets?
Expenses is fair enough, having a hole or 2 punched in the ticket won't affect you getting expense claims authorised!
when I used to claim for travel I used a credit card that gives you a receipt
Some extensive threads in the past, the matters in which I would hope will not need to be reopened and rediscussed, have pointed out that not all employers will authorise expense claims based on credit card slips, which is why some people wish to retain the original tickets despite that they are the property of the railway.
Do bus and coach tickets issued for journeys also remain the property of the issuing company ?