Simple. It is because they still lack in knowledge regarding crypto. If only they know how beneficial their volatility is specially this time, they will be surprised on how much profit they could make compared to if they will invest on fiat currency. We cannot blame them if they have no interest on finding out more what crypto is but we can laugh at them when the time comes where crypto becomes more beneficial and starts dominating the world. Not everyone will benefit on crypto for sure, only those who believed on it and never lost their faith towards it amidst the risk they take upon investing here.