Majority of people are not aware about bitcoin, and people who knows it will hesitate in reinvesting if price falls back, so these are two major reasons people don't like to use it.
yeah, i agree with the idea that people dont like to use it because it is possible to lose a lot of bitcoins in just a few days so they are scared of investing to it in my opinion
though they also dont like the fact that it is used for illegal activities really often so they dont want to be involved in any stuff that is connected with it i think, though those are just my ideas