I think people who say bitcoin is bad just don't really know what bitcoin is. They heard some negative news in mass media and think it is some kind of scam or financial pyramid. But when people will learn about bitcoin more they will understand how great this technology is.
in most cases, all negative statements carry a certain purpose in themselves, which feed not only to harm, but also to achieve certain results. In most cases, it is precisely today that the negative information background around Bitcoin provokes many to sell, and others use it to buy cheaper.