If some flaw is discovered in SHA-256 or other parts of the algorithm, like how MD-5 and SHA-1 had weaknesses, overnight the value goes to zero. Or if a basic widespread exploitable bug was found in most bitcoin stacks like Heartbleed, that went unnoticed, boom, value evaporated overnight.
You can based the entire world monetary economy on a single point of failure like this.
This is true, it is also true that no implementation breaking bugs have been found for a long time and you can also be sure that there are any number of people constantly looking for ways in which to exploit bitcoins codebase to either steal, destroy or create new coins.
Neither do tulips, doesn’t make them “a good unit of currency” or “not a massive bubble”.
But the core point bb88 was making is that it can serve at most one of those two goals: “store of value” and “good for speculation” are mutually exclusive. Something can be neither, nothing can be both.
You can based the entire world monetary economy on a single point of failure like this.