There are lots of things why people are feared on Bitcoin. Bitcoin is decentralized so it is not under any government and it also means that no one will take full responsibility if ever there's something wrong happen. Also its value is volatile so there are times that its market value will fall which is a risk as an investment since tgere's a tendency for an individual to lose money. But these things are just temporary i guess and maybe in the future these things will be solved and will make Bitcoin a better crypto.