With many people saving approximately nothing for retirement and hitting 65 with roughly $0 to show for it, even his modified example of having $300-400k after 40 years is... a pretty damn good argument for saving $100/month.

Whether that $100 comes from lattes or apps/micro-purchases or junk food or brand labels or holding on to your car 2 more years before you replace it or cutting the cord on cable TV or more frugal vacations -- is all up to the individual.

Sorry but if you've literally got a billion dollars, you might be able to advise on growing your money, but you are (almost certainly) not able to advise on frugality. It's almost as if the argument is that if you spend $5 on lattes, you'll mysteriously be a much richer person who no longer has problems saving for retirement. That must be one damn good latte.