What is wrong with registering and licensing guns?

I am reading this article Harper takes aim at gun registry. I realize that the gun registry has been unpopular, and seems to have been very poorly implemented. What does not make sense to me is the argument against the idea of registering guns, and licensing owners. The same people arguing against it have no problem with the rules which require us to register our cars, and have licenses to operate them. Why then does it not make sense to do the same for potentially lethal weapons?