Of course they are a nett negative on the tax receipts.
Same as anyone using the franking credit to offset their tax.
The whole system is designed to allow tax paid on company profits to be only taxed once.
You cannot single out 1 group and say they are costing government money, when everyone who is using franking credits are doing the same. That is how the system is set up. If you don't like it, then argue for double taxation of company profits.
