they do not really believe because bitcoin is not physically like a country's legitimate money and most people think bitcoin is a fraud
indeed it is difficult to make it difficult for them to believe that bitcoin is true, because bitcoin which is intangible like banknotes is valid in my country, until they think that bitcoin is just a fraud ..
Here also, people think that bitcoin is not true because it is a cryptocurrency and exists only in the internet and not regulated. What fired up their thought that bitcoin is a scam is because of the news that some people who invested their money on bitcoin got scammed, and that bitcoin is associated with higher risks because of its volatility.