Well, look at it this way. A financial collapse of catastrophic proportions will happen in our lifetimes. When this happens, and it WILL happen, BTC will rocket to the moon. So one could argue that BTC is a guaranteed investment to yield huge returns. Just how long you have to wait is the question. And i'm not talking about BTC price increasing as a result of of the devaulaton of the $.
This did happen, in 2008. The collapse that happened in 2008 is roughly a once per 100 year event. It would be very unlikely that we see another financial panic in the next 50 - 60 years (the span of the rest of most of our lifetimes).