I can not understand why this thought occurred to you? I have never considered and do not think today that altcoins will be able to disappear altogether, because I believe that today the crypto-currency world simply can not live without it, although maybe I'm just mistaken
Of course the altcoins will not die, it's just another fall, after which there will be another ascent. The market at the moment is very volatile and it explains a lot. Large players manipulate the market, creating panic in those moments when it is profitable.