Dumping game saves, emulators, modding games, piracy with working online, homebrew games, video streaming, cheats, and tons more reasons. if you don't want it though, that's your choice. I find it very odd that you have an interest in pirating DS games, but not installing CFW to your 3ds. Whatever works for you, though.
As far as there being another way to hack 3ds... I doubt it. Possible, but very unlikely. Since NTRboot works on ALL firmwares, even future updates, its unlikely that any hackers will be searching for more kernal exploits. You could kinda call NTRboot the "final hack."
lol, right?
F