What makes you think that Gates and Bezos were created by tax loopholes? And, what do you even mean by tax loopholes? Is postponement of capital gains until a sale event a loophole? Most of Bezos' wealth comes from his ownership of Amazon, which won't be taxed until he sells his shares. Changing that rule would mean Bezos might be less rich, but it would also mean that you would have to pony up tax money every time your house appreciates in value ...