The fear of the government is that Bitcoin is took volatile and that is true but if they learn about the Bitcoin history, they will all be aware of the right season to expect huge profit from Bitcoin which is going to be beneficial to the country economy.
If the government were to accept bitcoin as their legal tender, they can't lift this implementation up when bitcoin is not doing well. It is true that accepting bitcoin as a legal tender will help drive their economy by attracting more investors and encouraging spending. Now if bitcoin were to crash, businesses would have to up their prices which is not ideal for anyone much less the government. Knowing when bitcoin will rise, or fall will not do anything for the government but warn them about future challenges.