This is Why Landlords Quitting Victoria, page-122

Negative gearing is an investment strategy(not a good one imo but one some people use), why should it matter what the asset is? Either it's allowed or it's not. Some people negatively gear into property, some people negatively gear into shares, trying to say a property investor can only claim the costs against their income if they choose the right way to get a return from their investment is about as dumb as dumb can be.

I also doubt many who are short term renting are negatively geared anyway, they do short term rentals for the much larger return which I imagine would make it positively geared in the vast majority of cases