coolwhip, if I understand rightly, it sounds like you are making a distinction between habits and learning, but I wasn't making that distinction as they both follow the same process. At first we practice something deliberately and consciously, until it becomes automatic and unconscious. If this didn't happen, we would not even be able to stand up, let alone walk or drive a car. The complexity of mechanical actions would be too much. When someone is learning to drive a car, at first their actions are slow, deliberate and awkward, but once they can operate it quickly and automatically they can direct their attention to where it should be, which is on the road. If they had to think about everything they were doing, they would not be watching where they were going or be able to react in time if there is danger.
However, you do make a point about doing things too unconsciously, and there is a chapter in the book which discusses this. At first repetition develops fluency, speed and skill, but once it becomes automatic you can become insensitive to feedback and stop paying attention to bad practice. In which case he simply suggests you use a combination of automatic habits and deliberate practice.