This is not a cult. You don't have to defend the network with your lives.
It's highly unlikely that Bitcoin will 'die' unless there is a catastrophic event that brings down the entire internet and all of the hard drive's contents. The number of nodes that are present on the network ensures that there is sufficient redundancy. It also won't really matter that much if Bitcoin gets abandoned because there'll probably be a better version of the crypto available.
If you see the posts of users, most of them think that we have to defend bitcoin as OP mentioned. Idk why some people post things like this and blame every altcoin, especially Bitcoin cash and XPR, yeah, it's clear that there is shady marketing behind it but blaming BCH because it has higher block size and offers better transaction fees and speed, for me, sounds illogical.
So no, we don't have to defend anything, especially bitcoin. It's so strong that it doesn't need defence from you, see it's price, it's rising, going on the moon while you are on the earth, so, I think the answer is clear.