You could get the protection for the airline, or the airline could start to compete. Rather than contracting and cutting service, it needs to grow. Blaming foreign carriers for QFs problems is wrong. IF QF managers concentrated on growing the company, rather than cutting costs things would be different.
Why charge extra taxes on foreign carriers that carry pax to places where QF doesn't offer services, which is at the moment almost everywhere. If you want to go to anywhere expect London or LA you can't go QF, its as simple as that.
Tourism is a big earner for Australia. The the high AUD, and the limited services offered by the national carrier, means the tourism industry relies the foreign carriers.
Taxing travelers to help compensate for cr@p management is not the way forward. Look at how many seats EK carries out of Australia every day. QF needs better equipment (772LR?) and start taking these seats back by offering services to where people want to travel.