I prepare St Louis style. For me, its more appealing to look at and easier to eat, serve and cook. It fits in the rib racks better for more even cooking. (I've also left them alone before as well). I still cook the larger peices that have been trimmed off.
I too find them more aesthetically appealing. However, for me there's also the practical side as well; I use a rib rack and they fit "better" in my rib rack when turning end over end 1/2 way through my cook. I do however rub and smoke the pieces I cut off as they're a great snack for the "pit master."
they cook faster.
they cook more evenly.
parts like the flap you dont really want hanging off a rib.
the membrane is tough so i take it off.
they fit better in a rib rack.
just to name a few.