By that logic, there's no reason for more than one brand of anything. Litecoin needs no "reason" to exist other than one: Choice. That's by FAR not the only reason for it to exist, but that's the best one. I want an alternative to Bitcoin because I'm not willing to put money into Bitcoin, until I know Satoshi's stash has been demonstrably "burned" or redistributed, or otherwise provably destroyed. Litecoin IS Bitcoin, but younger, faster and running on a completely different network of hardware.