That is an extension of the over-scheduled kid during the school year.
I think that the crazy notion that you need 4,000 extra-curricular activities from age 3 mos before birth, excelling in & learning amazing life lessons from each, starting a few non-profits, and hopefully cured at least one major disease or solved a long-standing problem of humanity...just to get into a "good" school...is the bullshit which drives this.
That, and parents who are busy and want babysitters without calling them that...lol