Oh yeah, it's dumb. But I like to imagine a dad who spent lots of time getting the costume just right, working hard on getting the "ho ho ho" down to mask who he is, getting a burlap sack and wrapping a bunch of boxes to put into it. Alright, hours of work complete and...they're running away from me?! Oh no they don't!! Hehe, can't imagine anything but absolute frustration causing someone to make such a goofy decision.
Or he was just a jerk.