Mining tax was stupid and complex,it only taxed iron ore and coal.
The smartest accountants do not work for government,many mining companies that export resources never intend to make a profit and would never pay the tax,the mining tax should have been simple and a royalty charged on all mineral exports as a percentage of the sale price of the minerals, this would flatten out tax receipts instead of creating a glut of tax receipts when the economy is booming.
Multinationals are ripping Australia off and should not be that difficult to pull into gear.