Yeah that is a shame. They lifted the requirement for a few months but put it back again. I'm presuming they got a lot of calls along the lines of "OMGWTF my ObscureRouter2736xte isn't connecting".
Weighing up the service you get though, and the fact you can auction off your mandatory purchase for a decent enough price, it's worth it. They're miles cheaper than, say, Zen and still manage to give you up to 24Mbps and equally excellent service.
When you look at it like that it's suddenly not bad at all. I can't fault them one bit and I'm well into my second year with them now. 22Mbps sync, 2.3MB/sec rock solid, 500GB average bandwidth a month.