Hello!
If bitcoin died do you think people will lose intrest in other cryptos aswell? which altcoin would you invest in if there were no bitcoin?
If bitcoin die there are two options... BCH would be the first one, it could be the perfect coin to replace bitcoin. And the second option would be ETH, but this one will not make happy all the coiners.
If bitcoin die and ETH takes the control on the markets (with all alts basing their price in ETC) would be like take the market control from china hands and give it to rusian hands. Just like that.
I think coins like Monero or Litecoin have less chance to substitute bitcoin.