your opinion is highly appreciated.
It might depend on the reason why Bitcoin can die. In case when the death is due to total ban of Bitcoin as done by all governments or regimes then there is a possibility that Bitcoin death can also mean the death of altcoins. Now, if the reason can be other than that or it is within Bitcoin like losing the appeal from the market then there is a possibility that another coin can rise up to take the vacuum of leadership.
Yes, I agree, that only in the case of complete ban of Bitcoin would other altcoins too die. In other scenarios, like maybe too high transaction fees, or maybe due to price decrease/less appeal, due to other altcoins being independent of BTC, they will probably live, unless there is mass-scale loss of appeal for all cryptocurrencies.