What makes you think the end cannot come before pensions and mutual funds start investing? What if panic selling triggers a deep loss in value, which then triggers miners to shut down as the mining reward falls below the energy cost; if enough miners shut down, someone could pull off a double-spending attack, and when people see that it will further reduce their confidence in the system. The result could be that confidence in Bitcoin never recovers.

Or Bitcoin could just be a fad that slows unwinds and fades away, and twenty years from now we'll all be laughing about it over drinks. I can think of a few other technologies that were "definitely going to take over" and are barely remembered today...