Using ballast is just silly certain cars/drivers should be faster than others and adding ballast or reversing grids or in some cases just rewriting the rules is something one does for TV entertainment not a proper sports event.
That's no way to make it fair from an engineering/sports point of view. By doing so your basically just adjusting it so every car/driver combo laps at the same speed which defeats the point of motor racing, you may as well have a one car formula with drivers ballasted to ensure they lap at the same pace.
There must be a better more scientific way of regulating racing cars without having to resort to artificially making things even.