A zombie apocalypse would lead to a collapse in production and thus eliminate the ability to exchange USD for physical goods and services. Currency is just a points system used to allocate resources. It's a necessary evil. If we could allocate resources in a more effective way we would do it.

What resources does Bitcoin allocate? Isn't Bitcoin merely glorifying the concept of currencies but without anything to justify its existence? Since when did we ever talk about the USD (or any other currency) as being an end in itself rather than a means to an end?