I would have assumed they make that ticket only available yearly and with discounts to students or pensioners.
The way the Austrian ticket works (91 Euro per month for regulars, 68.5 Euro for teenagers/students/pensioners) is interesting. It's a yearly subscription, but you can cancel monthly. It includes all services, but train companies can sell you goodies on top (upgrade to 1st class, seat reservations etc.). I think that sort of system is more reasonable because it also enables some level of competition and it lets the rail companies charge higher prices for tourists.