No it's not. You just think so, because in your experience at ANU, students effectively have to engage with each other, so you don't see the real problem that most universities face: "How do we get students to really interact?"
For the majority of students, the best incentive is decent management, oversight, and support of student bodies by people who know what they're doing. In the majority of cases that I've seen, dropkicks fuck everything up with their own agendas. If the businesses and services are managed properly, student unionism is appealing to many students.