If your deductions mean that you owe negative taxes, it means that you owe zero taxes. I wouldn't be surprised if Bill Gates income taxes are close to zero as I doubt that he has any earnings, just capital gains with a lot of write-offs. Shit, I've ran a small business where the tax burden was basically negative (from investing savings and having very little profit) at first. Of course I didn't get the negative back but at least where I am there is income averaging, though not for wage earners.
If you're a business or a foundation, generally the tax system works in your favour compared to just a wage earner and the parent was talking about wage earners, "When you grow up and get a job and pay tax you will realise that you don't get taxed on what you own, you get taxed on what you earn" were the ACs words