In my case, I don't have all my savings in BTC. How do I justify investing in other things, like stocks? Diversification is one thing. Nobody knows right... maybe bitcoin will not take over... I think it will, but who knows, I have been wrong many times.
Just to mention one case of bitcoin companies, you have exchanges, for example, that are able to profit both in bull and bear markets. I think if the adoption curve is slow but steady, some bitcoin companies might grow faster than BTC price itself. Bitcoin already went from 0 to 1 trillion. Many bitcoin startup companies might be the next 0 to 1 billion. There's a lot of money to be made.