Simply because those people haven't tried investing in crypto specifically Bitcoin or they have fully known it yet. Yes investing in Crypto could be a lot of risks to take especially if you have no knowledge regards this but as long as you have taken your part like learning it you'll be fine, it is not that complicated. In regard to risk, the more risk it is the more profit you will get. Well, I can't also blame them because way back couple of years a lot of negative articles written about Crypto and a lot of becomes a victim of scammers using Bitcoin that is why it gains a lot of doubt upon adopting it. But now this will be different as a lot institutions are now venturing on this one.