This is exactly how I look at it. It may all go away in a puff of smoke, but that's why you don't go all in (although had I done that I would be retired now...hindsight and all). I'm sure the initial investors in Microsoft didn't see where that was going either. Which brings up another interesting side to digital currency. You have a few major applications of it:
1) Use it as an alternative save haven asset.
2) Buy low, sell high day trading <--- I actually feel there is some legitimate money to be made as there is a huge "technical analysis" following for digital currency. While I don't believe technical analysis amounts to anything, I do believe that masses of people believe it and will follow what the math appears to tell them.
3) Usable as a currency, especially between countries.
4) Play a long position, hope the world burns and digital currency reigns.
I by no means hope for #4, but that is my investment strategy. The interesting part for me, I am certainly not the only person doing this and if everyone held onto all of their coins it is actually counter to the growth of the medium. At what point along the way will the "whales" dump their coins for capital, real estate, or other alternative investments? Will be interesting to see it all play out, but not in an "OMG honey, I just ruined our retirement way".