the government not only because they do not get taxes so it does not legalize bitcoin but because the government can not control the bitcoin then the anonymous bitcoin makes the government afraid
this tax problem becomes the root of the bitcoin free circulation. because the government can not control it, then the government can not yet legalize it. this will continue to be reviewed for future technological developments, and this is inevitable.
Yeah, tax is really a problem because that will decide the income of a goverment and Bitcoin definitely doesn't support it, so that's why goverment never likes Bitcoin in anyway not like gambling.
for now there is no clear rules to regulate taxes from bitcoin. the issue that continues to be studied by the state that legalizes bitcoin, if all countries legalize bitcoin I think its consideration not only taxes, including money laundering is a crime that is very likely to happen if this technology is legislated in other countries.