I agree tax-payers shouldn't get involve in public-listed...

I agree tax-payers shouldn't get involve in public-listed companies. However, if government pays for BCS's interest in exchange for free BCS shares, then BCS will have more flexibility to run the business.

Business becomes inflexible and rigid if you got too much debt. If someone is paying for your interest, BCS can offer big discounts on toll to get traffic volume up.

Indirectly government does benefit from this project.
1) Create jobs for workers and collect tax from them. After Clem7 & BCS, which bank will lend money to toll projects? Not many new infrastructure projects will be build after this.

Telstra got all these national copper wires from govern's tax dollars to build. Now government paid Telstra $22B to buy-back those useless, old copper wires for NBN. Look at Telstra's sp and dividends.

BHP & RIO (which they refuse to share their railways) got funding from tax-payers to build railway lines dedicated for their mining (their shareholders). Now govern is taxing BHP & RIO.

2) Improve efficiency and improve productivity - more productive economy

I can't remember the figures, infrastructure experts estimated lack of infrastructures (mainly traffic jams) cost Australian economy many billion/year.

3) After many years, I think when the concession period runs out (may be 40yrs+) this project will be given back to tax-payer. Then government can keep the toll fees or becomes toll-free (I doubt it).