Simplified example, I have $100 worth of stock, I borrow $10 and pay 10% interest. I eventually have to come up with the $10 to pay it back, which will be post tax. And I'm paying interest on it anyway, which may or may not be tax deductible.
It would be the equivalent of me getting a home equity loan and having to pay taxes on the gains of my property when I took out the home equity loan.
What am I missing?