Theoretically what Vitalik said could also happen, even bitcoins could go to zero if they want. But I'm sure it won't happen, to much money involved and to many to make.
Agree with you, if the whales want this market to go to zero it will certainly happen. But I don't think they will do it because the market is so new and could make them more profitable in the future. Everything is only in the first stage so we need not be afraid
To such limits the market will not collapse. And here the question is even how much they can keep the low price of cryptocurrency assets ?!