If you don't believe in one thing you want it to disappear. So i think some people still condemning bitcoin because they don't want it or they don't know what bitcoin is at all.
Lack of knowledge I think that makes them to do that, they might not be understand the real purpose of this technology but in the future they have no choice but to adopt. Bitcoin is a great coin, and people should start learning this one now or they will be left behind by many people. Adoption is the best thing that you can do to enjoy better technologies.