I think the only way that Bitcoin will go die, is when the TOTAL BREAKDOWN happen, and what I mean about this is not just the internet, but every electronically powered devices or machines, all the power lines are cut down and no power at all, world wide. This is what will kill Bitcoin. I know this is a little off topic but you get the idea right?
Yes you are right. There is no other way to stop bitcoin because even if the government dont legalize it people will still use it. It can only happen in a way when all the power stuff will be down and this can only happen in a situation of third world war. Where the infra-structure will be damaged as a whole.