What do you think would happen to the rest of the currencies if for some reason bitcoin were to crash and the price dropped to 0?
Then most alts will go to zero as well only a few altcoins will survive but I do not know for how long such projects could survive since most people will withdraw their money out of those coins as well in an attempt to try to keep their money, most likely we will need a new generation of coins to try to make people optimistic again but it is entirely possible the market never recovers from such a thing.