Vacancies

The second round of university and TAFE offers came out today. Along with that there was a list of courses in which there were still vacancies.
I wonder why there are vacancies in any courses, particularly in courses like engineering. Don't we need engineers? Or is there some other reason for failing to fill those courses?
We almost certainly have too many students attending universities. All generations claim that standards have dropped but I believe that current complaints about dropping standards may be justified.
Cut off marks should not be everything of course. There are courses, such as teaching, where other abilities and personality also count. Nevertheless cut off marks are important in the way the system is run.
I suspect the matriculation system really needs an overhaul. I wonder what would happen if I applied to do any of those courses with vacancies? I never matriculated, most of my fellow students did not. It was a rare thing once. People went on to training for a number of things without it and some of us even went to university. Is it really so different now? Learning styles have changed of course. I cannot imagine sitting in a lecture theatre, reading set texts or having to turn in essays on specific topics.
I think it may be Warwick University that gives very good students the option of studying alone. It must require considerable staff input as well as student motivation, application and maturity. What are the results like? It's an interesting thought.