Bitcoin hold a very important rules for the alt coin, bitcoin is the one that glued all the alt coin, if bitcoin fall to a crash, there will be an impact to the alt coin, but alt coin and bitcoin could walk in different path, if let say bitcoin keep on crashing, people still can find other coin to invest and that can caused certain alt coin to rise and possibility to replace bitcoin place, so as long as people still interested in crypto, crypto will never die. For my opinion without Bitcoin altcoins are useless the reason why is because before you can use altcoins convert into Bitcoin and convert Bitcoin into the fiat money. This scenario showing bitcoin are most important coin in the world of cryptocurrency using volatile internet connection.
What ? Damn, bro. I cannot imagine what will happen with Altcoins if Bitcoin disappear. As far as I know, all Altcoin's price is influenced by the price of Bitcoin. If the price of Bitcoin goes down, I think the price of most Altcoin will also go down. If Bitcoin goes up, I think the price of most Altcoin will go up as well. But the rise and fall in the price of Bitcoin-affected Altcoin is erratic and not always the same. It could be the decline and the price increase many times over. In accordance with market conditions and news. There are cases where the Bitcoin price rises, but the price of a cryptocurrency drops dramatically. It all depends on ICO people and managers.