The problem with University Hackspaces is that they aren’t self determining in any way - they are fairly strictly tied to the university and their policies. Furthermore, they have significant funding streams, already agree discounts for their students, and don’t have a community orientated objective unlike many hackspaces. Never mind the simple fact that it’s almost impossible to access them without paying crazy fees and doing a degree.
Then there is the simple fact that there are a fair few universities that tend to control things in groups, and we don’t want them to be able to hijack this group by joining as full members and swamping us out. Thus the non-voting associate side seems sensible for university hackspaces.