Tax relief (negative gearing) isn't exclusive to property. Given the orientation of hot copper I am sure there are many margin loans, long term investors, traders and short sellers who minimise their individual tax by investing in Australia.
A new or newly renovated property has far greater depreciation available - one of the larger contributions to negative gearing calculations. Thus investors are incentivised to build, increasing supply.
Hopefully those landlords who bought years ago have refinanced, and invested further in residential property, increasing supply.
Your 'external' points should be your focus - a grasp of the tax system that MAY be applicable to some (not advice) above hopefully betters every Aus tax payer to improve their financial position.
