Any business or scholastic entity that attracts douchebags or promotes douchebaggery to the extent that the vast majority of the members of that entity become douchebags. Douche factories are frequently law firms, real estate agencies, fraternity houses, or the University of Tennessee.
Hey, why did Steve change his name to Brody, start over-gelling his hair, wearing sunglasses upside down and backwards on his head, and carrying his man-bag around everywhere, even to the movie theater?
Yeah, he was fine until he started working for Remax and driving that smart-car.
Oh man, that place is such a douche factory.