This is fair, even at reddit's scale the uni subs remained small. But certainly unimelb/Monash/usyd/unsw will need communities at some point (even if not now) judging by the popularity of their subs

I disagree, (as a uni student) - the types of discussions in these communities are specific to each uni (staff drama, course selection, urban legends, etc) and not fit for an Australia wide community, where the only commonality might be HECS news