Shareholders stump up the cash to establish a company and all...

Shareholders stump up the cash to establish a company and all the assets it needs to run, and then they employ a board and management to run the company.

Unions collectively bargain with the company to get the best possible deal for union members.

Unfortunately, if the union has enough clout and is in a dispute with management that can't be resolved, both sides lose as the company has no mechanism to continue employing happy workers and replace unhappy workers. Collective bargaining often leads to collective gain or loss.

Shareholders lose either way and have to shoulder the risk/cost of union influence, and people who would be happy with the job lose too because they are effectively locked out as unhappy union employees are appeased rather than let go.

I think Joyce probably had to make the decision he did anywy - imagine the result if an accident occurred due to Qantas flights being kept in the air while being serviced by engineers in dispute or on intermittent strikes.