Another important thing to note is that you're likely a member of a very privileged class, by virtue of being on HN. You likely have a bank account and a credit card. Not everyone is so lucky, and Bitcoin serves many of the same needs you fulfill with the traditional financial system.

Then you have remittance. Imagine you are a Somali immigrant living in Michigan, and you'd like to send money to your brother in Xamar. How do you do that? It's legal, but to my knowledge no US Bank operates in the region. Bitcoin world's as easily to your brother as it does to anyone else.