Howard went to the voters with the GST as his major proposal and won the election.
The legislation was passed in the house.
Howard did not control the upper house.
Labor opposed (in the senate) what the electors had voted for and what the house had passed.
That empowered the Democrats to have the balance of power.
The Democrats used that power to amend the legislation - badly.
Labor is thus responsible for the current GST being deficient due to the amendments.
None of the analogies that you got from the voodoo economist remotely resemble these facts. Labor has never remotely attempted to repeal the GST. e.g. the Libs repealed the mining tax and the carbon tax.
That's my final effort of trying to explain simple logic.
