If I were to be in their shoes, I wouldn't be taking that risk. Just one wrong decision, they won't have a chance to fix it.
Well he knows the risk and he take it together with his family. That's why people is very different as far as their risk aversion, there is no difference but us gamblers, traders and investors. But you can't say that he did make a wrong decision. Just look at the past history of this community, you can see pages of regrets specially those early bag holders because they didn't know the future of bitcoin. What if the price goes to $20k or even higher in the next coming years?
If he only invested a portion of his family money in bitcoin then that is absolutely correct, but investing all in bitcoin is too risky.