Can you tell me/us the reason(s) why you don't want to update your iOS version? To be honest I really don't know any reason to stay on iOS 6. I think iOS 7 is 1.000 times better, not only from design, also from all kind of really awesome features. And im about 2 month there will be iOS 8 which is ever better.
I absolutely despise the visual design direction Apple seems to be obsessed with now. I can't stand the way it looks, including the animations. Also, I would lose my reel-to-reel interface in the old version of Apple's Podcasts app which I use and enjoy fairly frequently. I don't really care what anyone else has to say on the matter since I'd prefer to lack the new features and not hate using my device for as much of the day as I do. It's a similar situation on OS X with Yosemite fwiw. My devices will continue working just as they did when I bought them, but if I can improve something through their being jailbroken while maintaining the beautiful aesthetics, I won't hesitate to do so.