I'll jump into the fray (fire?) and give a few solid reasons for using it:
I'm trained in using it. My cave training has taught me to use it, and I've found that using a 7' hose in an OOA is infinitely more comfortable and manageable than trying to bend your neck just right and be chest to chest with your buddy in an OOA. I've never done a real life OOA, just lots of drills (in class and "self-inflicted") and my exiting a cave or swimming to the surface is INFINTELY easier than trying to do it while untangling your legs and bodies while using the short hose.
I treat every dive like a cave dive. When I get back into a cave/wreck after doing OW diving, I don't want to be unfamiliar with the gear for it. My gear changes very little when I do open water diving. I don't take a primary reel, but other than that...my gear doesn't change. This gives me an extremely high degree of familiarity with my gear and when I need to use it, it's a natural act.
Third, it's personal preference, which is what this all boils down to. I like the long hose...it makes sense to me and it's logical. And if it works for you...why change it?