Let's imagine, that there are people who want to build spaceships for bitcoins. Why they will be more competetive, then the people who build spaceships for conventional money or for the own corporate shares? Isn't the gap between conventional money and bitcoins too huge ? Do you really believe that the profit from bitmoney will allow to close that gap ? Can you be alive for that long time ?
They are saying this simply because they believe some day 10 BTC will be worth as much as a spaceship.
Nobody can answer you how long it will take or if ever. It's pure speculation.