One good reason to eliminate it is the abuse of current system via interest-only mortgages, whereby a landlord will deliberately keep their interest bill high in order to get the state to subsidise it. He is better off keeping his spare cash on deposit at 2.5% approx than paying it off his mortgage (where he will save only 58% [100%-42%] of the 3% interest rate). We might as well just throw our taxes straight into the landlords and the banks instead.