Even when you showed people back then that in their particular situation they'd save more (in many cases way more) they were still against it because of the percieved mental addiction to their emotionally sacred mortgage interest deduction (wich also helps pump up real estate bubbles that later crash).

Way too many people (voters) would rather pay more at the end of the day than lose the perception of their plethora of savvy deductions. There's not much you can do with that intelectually.