"I am repeatedly told by some on this site that to go to the point of imbalance is natural, we do it all the time when we walk. Then why mention it if it happens naturally."
Because many people who walk in the studio door with an outstanding executed walk get it all wrong as soon as they set their mind to dancing "correctly".
Yes, there are a lot of things you need to drill precisely to dance well. But you will also need to develop the same ease and efficiency of movement which you use when you are not dancing - and imbalance is a key part of that.
The other reason is that it's a lot easier to walk efficiently by means of imbalance when your legs are straight. Once you start bending your knees to create dance actions, there's a tendance to "sit down" as your knee bends - to also bend your hip, so that your weight can stay stable over your foot. But to presever the same easy and efficient action you have when you walk without bending your knees deeply, you will have to learn to project your weight even when you are bending your knees.