they have not understood in detail about bitcoin, crypto currency and everything related in it therefore they are not interested in this. others assume that this has a very big risk. so they are frightened to join
They have no interest in bitcoin because they believe the negative news spread about bitcoin or it could be because they do not have factual information about the truth that is shared by a trustworthy person. If only they will give bitcoin a chance and the goodness it can bring to their lives these people will definitely welcome bitcoin in their lives. However, proper caution and complete information should be shared to be able to avoid problems in the future.