It seems every day on the calendar is devoted to something, except megalomaniacal dictators who want to take over the world. If skunks get a day, and librarians get a day, and moose handlers get a day, well, why can’t Hank Scorpio and co. get one too!
Seriously, we need a day for the proper villains because we NEED a common enemy to fight against, to show us that what we have is worth fighting for.