Play out the end of an asset bubble in your head. Lots of people sell their assets, and now have dollars. The job of our policy makers is to make sure dollars don't increase in value at all, and don't decrease in value too quickly. But if lots of people are exchanging assets for dollars, the demand for dollars makes the value go up. Our policy makers will take a variety of actions to make their value go down by up to 2% a year. If we're lucky, they'll be able to stave off deflation.
So if you've sold your assets and want to store your value, you really want some sort of ledger with a predictable supply so your value can go up, not stay the same or decrease by 2%. Gold is traditional the ledger that people seek when these sorts of things happen. But enough people will choose Bitcoin to raise the price significantly, which will make others choose it as well.
Gold might be the right bet, but Bitcoin is a more functional ledger (easy to store, easy to transfer, etc.), and the upside is higher. But again, maybe I'm crazy.