Originally the holidays celebrated 2 extraordinary President's Washington and Lincoln. It was consolidated into one called President's Day so to make room for a day to celebrate MLK .
All 3 men are worth celebrating . The office of the Presidency ? Not so much.

The framers never intended to create a king by another name . Washington aware of that did not run for a 3rd term to avoid the perception of a royal executive .
Members of Congress did not know how the respectfully address the President . The titled address suggested included “Your Highness” ; “Your Most Benign Highness", "His Exalted Highness” and ,“His Elected Highness.”
The constitution prohibited titles (article 1 Sec 9 clause 8) which more than proves the intent of the framers was to create a position of modest authority and limited responsibilities. Mr. President would do .

What has evolved is an elected king who with a 'pen and a phone' ,with the power to wage war ;set trade policy ;and legislate through executive order despite the Constitution giving that power to the Legislative branch. Today the President has the power to force private industry to make products the President decides is needed .

Congress over the years has willingly ceded powers to the Executive that are clearly their constitutional obligation.

So while individual presidents can be praised or condemned for how they have wielded power . The Presidency itself is not something worthy of a national holiday .