The point, and one of their selling points, is the backrest feature. I have a herniated disk in my lower back, so finding a way to use my improved stock seat and get a backrest after removing the Corbin seat is what prompted me to post this. There's all kinds of bike luggage out there. I have four Nelson Riggs sissy bar bags, Triumph throw-over bags, and a few other pieces besides....
The BF bags aren't for everyone, of course. But they solved my need for a backrest. That's all.