Except that it often DOES work.  JFK did it.  Reagan did it.  Bush43 did it.  Even Obama did it (to a smaller degree).  And in all those cases the economy saw a significant surge (although less-so in Obama's case as GDP growth stayed under 2% for his reign).  

People have this tendency to look at things in all-or-nothing terms.  Lower tax rates on a broader tax base (i.e. fewer deductions) can absolutely produce more revenue and boost economic growth.  But that doesn't mean EVERY plan that cuts taxes does that, or is reasonably balanced.  As with ANY plan, it can go too far if taken too far.  People really need to learn more about the Laffer Curve effect.