Well I think its mostly the bad name the bitcoin itself has because of the criminals that are using it, but that should be no risk.
The other thing I'm thinking is that people are to scared to invest in it because its still a risk you are taking.
Criminals use all currencies not only bitcoins, then why people are pointing finger only on bitcoins? People should not hate it only because of this one reason, they should see other benefits associated with it.
They will stop if they know that you also can lose some money and that will be not good. But its better to hold if the value is low.
I hope later that more people can have some good profit of it and that they can make Bitcoin more popular.