I can't decide if you're trolling or not, but I'll bite.
My ipod touch is jail broken because I want to be able to compile and run any app I want, without it being vetted by apple first. I want to be able to retain apps that apple has pulled from the app store. I want to be able to run a full dev tool-chain on my ipod if I want to, have full directory access, and full control over *my device*. I want to be able to customize my UI more than apple's anemic built-in abilities. I don't want to get an android device because there are a lot of things I really like about iOS, but I do want to customize it a bit.
2 other points:
a) I don't need the warranty as much as I want these features, and you can sure as hell bet there are a lot of others like me!
but also, b) in respect to , some people also happen to like to hack their devices, make them work in ways they werent marketed to.
My xbox at home serves as a streaming media center more than as a game console, and it used to function as server before being retired in favor of a mac mini (both btw running debian linux). Back when I lived a college house my beer fridge had temp sensors purloined from a broken imac. The list goes on
Hacking is fun, mate!
True, it can be fun, though the few times I've altered a device to open features I was using packaged tools or instructions so I don't consider myself a hacker. I just think as much as it can bring to a device there is much more bad that comes along with it.
You can hack other devices like an AppleTV or PS3 but in the end most of the reasons you hack them could be done with more elegance on a cheap linux box running something like XBMC or Boxee. The big issue with hacking is the doors it opens and the general abuse of it with a mindset that, "what I'm doing is not really that bad, really."
People share mp3s all the time without a second thought because the culture has already embraced it as no big deal. Call me a prude but theft is theft and when people hack and then try to justify it with 1 or 2 minor legitimacies while also using it to do things like tether illegally or share apps with friends they are already guilty of stealing.
I have been guilty of it, and have seen others get ruined by it when they casually walk into a fed trap. Fortunately I've gotten my wake-up call by the misfortune of others, learned my lesson by observation instead of experience. Companies have a right to protect their products, afterall Apple wouldn't make an iPhone if there was no business in it.