Imagine two worlds:
World One: You work for The State, or are a student at a State-run school. National holidays are on Mondays. The next day is Tuesday. Back to work for most people.
World Two: You work for The State, or are a student at a State-run school. National holidays are on FRIDAYS. The next day is Saturday, Another day off for most people.
One of my favorite holiday experiences was on a 4th of July that fell on a Friday. I had a wonderful time, and the next day was a Saturday. That was the best part.
I had the holiday, and THEN I had the weekend.
It doesn't work the other way for Mondays.
Yes, the long weekend is good in itself. But the Monday off has Tuesday and back-to-work looming.
A Friday holiday has Saturday looming.
More to the point, it's probably more respectful of the spirit of the holiday in question if it's on Friday. More likelihood of parades, and of people showing up for parades. Fridays can be the start of a celebration or memorial, instead of their end.
Whether it's Memorial Day, Labor Day, President's Day, or whatever, make them all Friday!
Who are you hurting?