Most powerful members of government, lobbyists, and others who control things behind the scenes, should love Bitcoin because they could use it to receive their bribes more anonymously, and that's how government normally works. It is to most politicians' selfish advantage for Bitcoin to continue being legal. Bribes and secrecy for themself are the main motivations that make government happen. If governments start opposing Bitcoin too much, such corrupt politicians have a lot of motivation to keep it around. When most politicians say Bitcoin is bad, I see that the same way as if a Politician had said they don't want wars to be fought.
Honest politicians and their citizens should support Bitcoin because decentralization of the economy eventually leads to ending government corruption and solving other big problems. Corrupt greedy politicians should support Bitcoin because they are impatient and want their bribes and funding for their criminal activities quickly.
If it was intended or not, Bitcoin is a major move in the negotiation between the underground and governments. We offer to help governments be more corrupt temporarily but not long-term and in return we get a decentralized economy. I think both sides can agree on that.
Honest politicians will be scared that a decentralized society diverges into gang violence and general disorganization, but we will design solutions for that emergently, like Bitcoin is an emergent solution for the economy. There are very smart people working on decentralized solutions to all major problems of the Human species. Governments, please let us solve the problems you couldn't.