You comes with an oldest argument which government tells from its start. Like terrist funding, kidnapping payment, drag dealing its worst example in todays world. And its like a useless example for bitcoin. That's why government also didn't tell that bitcoin use for criminal offence because they know its useless now for banning and people now understand that. But government now gives an excuse like economical crush on share marker if people invest in only crypto then share market will crush. Companies unable to increase company values business might shut down. This are now todays excuse.