Presidents Day is not for "all USA Presidents."  It became a federal holiday by combining the holidays observed in SOME states for Washington's Birthday (Feb. 22) and Lincoln's Birthday (Feb. 12).  Now they just calendar it between the birthdays of these two presidents and call it Presidents Day.  It combines two former holidays in February into one. I can remember getting both days off as State holidays in California when going to school in the 60's - 70's.

That's an interesting bit of historical trivia.  But of course the perceptions change.  Kind of like how Christmas wasn't always about a jolly man in red suit living at the north pole,  or previously about the birthday of a religious icon, or previously a holiday about the winter solstice/new year celebration.