I'd be happy to take a 50% pay cut if my income tax was cut to leave me no worse off. That would allow me to compete globally in the labour market. No political party is going to agree to that, however. The government's coffers would be a little worse off but I would still be spending the money in Australia, generating economic activity, paying GST and not drawing any benefits.
As it is, it looks like my job's going to disappear offshore meaning the tax is lost, the money is not being spent here leaving retailers worse off and I might start drawing the dole.
I doubt Gina's motives are about anything other than looking after Gina but our international competitiveness is about more than just salaries.