I can assure you the Unions played a minor part of the closure of the Whyalla Shipyard it was pure economics plain & simple.
Yes it is simply economics. Australia is only internationally competitive in a few industries. Punishing those industries to subsidize uncompetitive industries will only lead to failure.
Australia car manufacturing has said for 70 years they will one day not need subsidies. I guess they have given up on that lie.
Australian's overall have a very comfortable lifestyle, with lots of safety nets and targetted support. Not saying this is a bad thing just pointing out that all this comes at a cost. We can afford it now no problem, whether we can maintain it into the future is another question.