Why not? If AS meant for this sale to be truly useful for most of us.
And we're not talking Thanksgiving, July 4th, Xmas here.
Yeah Memorial Day, spring break, Labor Day, mid-winter break, etc, etc are also quite busy. But travel-heavy times are generally the only times we can travel for leisure. Same goes for most of our circle of friends/colleagues.

So it just proves sort of the obvious... these flash sales are pretty meaningless to many of us. But if you have a more flexible situation and are content with AS only offering unpopular dates and times on its flash sale, then good for you.