There's one thing I'm sure of. If the hard fork doesn't wipe out Bitcoin, It'll definitely scare People, Not just from Bitcoin, But from Cryptocurrency. I really can't believe Bitcoin is the subject of matter for a hard fork. A split in the network would be fatal.
No, one side will die and the other will remain, simple as that, no wipe outs and there's no reason for people to be scared. Bitcoin was designed to be upgraded with hard forks.
What's certain is that the correct solution (SegWit or BU) will remain and be used, while the other will die out.
Even ETH is doing fine, that situation was far worse.