No wonder the govt is going to ax negative gearing except on new houses.
There was an attempt to disallow negative gearing on properties back in the 80s. But they soon brought it back in, because of the backlash, and also, it caused such a lot of rent raises. Rents are quite high enough already.
There is also the banks - I don't think they want negative gearing on properties taken away at the moment. And they are a powerful lobby.
In general, one should be allowed to write off borrowing costs for an investment. Business is allowed this, and so should individuals be allowed.