I treat it like a security for now. I'd like to use it as a currency at some point in the future after it has more widespread adoption. I see it kind of like the internet in the late 80's/early 90's right now.
I'm not an expert on the technical hurdles, but I think the lightning network can resolve most scalability problems.
I can't speak for everyone, but I have faith it won't go to zero because I think it solves a real problem and that people find it useful. As a crypto it is unique because it has first mover advantage and is completely decentralized. And the longer it's around, the less likely it is to go to zero.