One major reason is the higher fluctuation rates that occur in the crypto industry. Your 10K can become less than 7K in less than an hours which is very pathetic and won't happen in the real world that we all know so when people see this, they do lose interest in accepting crypto.
Another factor is governmental organizations saying things to pollute the people from accepting crypto. They are know crypto is the best but they do not want to tell the truth about it and they keep beating about the bush concerning crypto matters.