I've never been a fan of the "if you don't like it, you can leave" argument because it implies there's some other place someone can live that isn't controlled by a Mafia-style coercive entity.
Some things are morally wrong and should be prevented by civilized, empathetic humans. We don't say things like "if you don't like child/spouse abuse, you can leave" or "if your don't like slavery, you can leave" because we recognize these actions as immoral and unjustified. Even then, these outrageous claims are more logical because they imply there is a place on earth the victim can go to escape the abuse. This is not the case with government. Accepting their monopoly on the initiation of force and saying it's up to the victim to find a country which won't be as bad, to me, is similar to justifying what is inherently evil. If slavery is taking 100% of my income, at what percentages is it no longer slavery? Saying government owns everything may make us feel better, but I don't see how it gets around the realities of theft/extortion.
But I guess many don't see government as evil. They see it as a force used for good and evil. Maybe they are right, but I personally can't get around democide. Any organization that is responsible for 100% of war doesn't get a pass.
RE: Perception changes Everything - Is Taxation really theft?