Bitcoin will die only if the price of bitcoin falls to zero level but I don't think that is ever going to happen as price will keep on going higher and higher in future as and we will see more people start adopting bitcoins in near future;
Even if Bitcoin was $0.00 the transactions of the coins would remain active. When or if Bitcoin reaches that price then people would have the choice to either pay for things with Bitcoin decimals or using another barter product. For the price reaching $0.00 another type of payment would get released by a higher class individual/individuals and digital transactions would get used a bunch more than it is right now.
Bitcoin would die if the whole system just stopped functioning (Blockchain doesn't have any new confirmations, the wallets won't sync, etc).
Even what you are saying might be true, but with the price of the bitcoin reaching a low value the number of people using it will keep on decreasing and although a few people will keep using it that want be enough to keep it alive because it needs more than just normal people to use it but also investors and places where it can be spent on.
Otherwise those same people still believing in it will eventually stop using it too it will be just a waste of their time and effort, and personally I dont see that happening at all.