Greenslopes: wrt to the mines, they are in a slightly different senario - those expensive bits of kit don't take that much time to train to operate, whereas aircraft can take 5-6 years from numpty to captain.
Rex seems to take the opinion that they can train their way out of the current prediciment - they can, but they haven't started early enough.
Their salaries reflect that they cannot get enough people in. The employees don't pay for the training because of two reasons:
They need trained people (ie capacity) NOW, not when the employee can afford it.
The employee can say "nup - I can go elsewhere".