Since when are we "normalizing" Monday games?

Years ago, most league games were held on Saturdays, with a few Sundays here and there.
Now, Sunday games are the norm.
It seems we are trending toward Monday games now.
The SoCal "College" Showcase had 1 game Saturday, 1 game Sunday and 1 game on Monday afternoon. (And NPL playoffs also had a monday game)
I AM in favor of not playing 2 games in a day. But we have about 6 weeks of school left- Why are we scheduling Monday games while kids are still in school? (It's hard enough to leave...

Since when are we "normalizing" Monday games?