It is still strictly worse for the repeat riders if they get a card valued at 10.41 than 7.91. The only reason for the city to even allow someone to do it is to

It is still strictly worse for the repeat riders if they get a card valued at 10.41 than 7.91. The only reason for the city to even allow someone to do it is to underhandedly get more money when someone inevitably loses their metro card.