They can't control bitcoin if the government wants. Bitcoin is really out of the reach of the government. The government has the power to control them only on certain exchanges if it wants to. Bitcoin is a digital medium.
Government can undo and do whatever they so wish with bitcoin mate, don't underestimate the sovereignty of government as a body. A tweet by US alone can do immense damage to crypto currency.
I think the government should legalize Bitcoin.
This would be difficult but with time, things change and I believe with more adoption, chances are high in the future.