With the dramatic increase in ease of transportation and the incredible decrease in the amount of time required to travel between far-flung areas of the United States, representatives began spending more and more time in Washington and less and less time in their home districts.
Washington's birthday is worthy of celebration - he is one of the greatest men in history. But Washington himself would likely have seen celebration of the office of the presidency itself as monarchic in nature.
Let's assume for the moment that the logic behind Presidents Day is actually sound for certain presidents. Why not have a separate holiday for Lincoln and one for Washington - as we used to do, before we became so concerned with the 'Every President Gets a Trophy' ethos?