Now that's concerning if not unexpected. PRTs are hard to carry around for long periods and create enough problems already.
Most people currently prefer to use ticket machines if they are buying singles or returns for immediate travel. If credit card sized tickets are no longer available, that will encourage more people to switch to e-tickets to avoid having to carry around paper. So if e-tickets become the standard ticket medium, that will drastically reduce the number of tickets sold from TVMs. Hopefully that will mean Monday morning queues will become the thing of the past.
If you go to countries where mobile or smartcard ticketing is common, queues at ticket machines are rare outside airports and main tourist destinations.