I remember a thread complaining about the length in this forum recently aswell. I do hope they gonna come up with something similar though! Or start like a second veteran reward, starting with 4.0...

To answer why they dont let us pay for more than 180: I would guess it is to avoid complains (or even law sues) if anything about the game changes (or even, the twelves might safe us, even shut down) they wont have to deal with unhappy customers, telling them they want their money back because this isnt what they've paid for.