Physics of downward firing woofers

Why call each other names? Especially for no good reason.
Well, downfiring bass doesn't sound like a great idea to me either but I would not judge it until I hear it in each particular implementation, including room.
Bass is difficult to manage, anyway, so sometimes solutions may look counter-intuitive.

Kef Reference 3~2.  I have a pair.  Two bass speakers in each cabinet.  One firing down, the other upward.  Both held together with 'force canceling rods.  An OK speaker, they have provided me many years of happy listening.  If the idea was so good I believe Kef would have continued on with the technology.
http://us.kef.com/explore-kef/kef-museum/1990s/reference-series-models-one-two-three-four

Gravity has absolutely no audible effect on a downward firing woofer's performance. None. A speaker cone is extremely light and its performance relative to the pull of gravity is meaningless unless it's a 172 inch cone, and if it wasn't, cones facing forward would also be distorted due to gravity as they'd sag ("cone sag" isn't a thing unless maybe you get a paper cone wet from something like spilled beer or groupie vomit)…or facing up…facing anywhere. Also, I own both front firing and downward firing woofers and they both sound great on the wood floors where they woof...

+1 @wolf_garcia  I liked the groupie vomit reference😲

Trust me…you don't wanna know the details.