To be fair to them, NUS itself has consistently backed the AUT in their pay claim and their industrial action and continues to do so -
www.nusonline.co.uk
Thats not to say of course that the posts on this thread have not been almost entirely correct, that NUS is a fairly ineffective political pressure group, and thats largely to do with how disconnected it is with students.
The question of whether students should have to 'otp-in' to the NUS and maybe pay subs is quite interesting I think. From a left perspective, perhaps with increasing numbers of people going to uni (and then into jobs), maybe it would make sense for the left to back opt-in membership if it meant that students gradually realised the value of having a national union, representing students and changing government policy, and become ingrained with ideas of collectivism and solidarity through that. (Although i think that the NUS is quite shit politically, they do have influence on legislation on small issues like mature students etc, just not on the key funding and marketisation of education issues.)
However the problem lies partly that anyone involved in NUS thinks opt-in membership would be the apocalypse, but mainly IMO that the members of NUS are not students, but student unions, which are funded by their parent institutions and provide all the representation etc to their college/uni that a new NUS would want/need to provide. That universities move up the league tables partly based on how much they spend on student development (i.e. everything the SU does except commercial activities) means that local student unions would never disappear if NUS did, and only the sabbs who were really committed to collectivism and solidarity would encourage people to spend money joining an NUS rather than spending it in their own SU bar. I'm sure that right-wing sabbs would also simply create a sort of 'presidents network' that could represent students to government on education policy.
At the moment discounts at a few retailers and the occasional quote from an NUS officer in the paper are all that NUS means to most students. Actions by governments in the last 20 years have restricted what local students' unions can do, and institutionalised them by basing university league tables on things like how much influence students can have and how much is spent on extra-curricular things. Whether thats a good thing for students (in a narrow, short-term sense) is debatable, however its definetly not a good thing for people who think collectivism and solidarity are very important both as students and in later life, or are committed to major social change.