Here we are "function of government", there can be many different functions of government besides the conventional ideas that governments should defend the country, the citizens, liberty and property. On of the important functions of government is to establish justice by protecting those that follow the laws, and creating peaceful environment for those people. They are not doing that, most of the countries are corrupted and they think only how to please different corporations.
If some local business start to accept bitcoins and skip paying taxes, that business will be closed very fast. Bitcoin is still without any regulations in many countries, but that doesnt mean you can just start using bitcoins in your store without any consequences.