The can is a superior package in many ways. It's lighter and more compact, making for easier transportation. It chills quickly. It's easily recycled, and consumers can flatten them if they like to save space before they do that. It protects beer from light. (Light, and not temperature change, causes skunking, ultraviolet light to be specific.) Canned beer has less air, which means the contents will stay fresh longer. Canning lines are much cheaper than bottling lines, reducing the capital required of the brewer. I would guess that the machine is simpler to operate and repair, since it doesn't require a labeler.