Just make what people want! It ain't brain surgery. If people are rooting your device you better scratch you head and figure out why. Perhaps next month you might not be selling any devices.
Every USB device I have ever been handed since usb first existed, I have pointed either midnight commander or ztree at and started digging to learn, how does it work, what's the dir layout, what kind of executable files keep it going, how are they compiled, how can I tweak the theme, sounds, etc, How can I back up the entire thing for possible Rollback. Because more than likely, I don't like the theme, don't like the sounds, and want to see if there are more things the device is capable of, and I am scared my data might disappear with all the crazy government laws and cruft going on.
Nothing is stable anymore, one day the book is yours the next day it's deleted. One day your mp3 player works, next day it's bricked, one day the GPS is great, next day it's bricked. Dear manufacturers of electronic devices, MAKE what people want, quit putting so much damn protection and secrecy in. It's NOT healthy.