That is why "consumption" keeps it fair. You spend you pay. Period. Think about it.
And another upside is that it turns all of your disposable income into a potential IRA. If you save money then no tax on that money (or its growth) - until you spend it. Will effectively do away with the (ridiculously low) $3000 limits on IRA contributions. Anything the gov't can do to encourage people to save for the future is good IMO.