Investors need to be losing money for negative gearing to do them any good, and it won't magically turn that investment into something profitable.

It is helpful if they're speculating on a big capital gain. In fact that's one of the recurring criticisms of negative gearing - that it encourages speculation and inflates property prices, neither of which are good things for renters.

People have, inevitably, used it to engage in various tax-reduction schemes, with varying degrees of succes (see the 2004 Australian High Court case of Hart v Commissioner of Taxation for an example of that _not_ working out). This is not a good thing for renters either.