I think it's the initial reaction for someone who has zero knowledge to fear Bitcoin, I myself back then used to have doubts about Bitcoin, later on realizing how legitimate it is and how big it will be in a few years, looking at it now, Bitcoin is still feared by some people, but with technology advancing and people slowly learning how important Bitcoin is or cryptocurrency alone to a lot of people.
I think these ordinary people can still learn about everything about Bitcoin, the lack of knowledge about the market and Bitcoin is one of the reasons why some people say that it's nothing but a scam, then they later on realized how rich they would be if they bought back then.
If they focused their minds and open it up not just that doubts to conquer everything about Bitcoin, the potential is high and the benefits to those who take their steps learning this system is really good.
It's very common to everyone who have zero knowledge about this industry to doubt and to fear, since it's deals with money.
They don't want to lose so some are not willing to take steps instead of pushing forward they forget about it, missing their opportunities to take advantage of what Bitcoin have to offer.