I never said you couldn't carry your weight forward on your foot with body alignment problems. If you do however, the movement quality is not likely to be smoothly even like the advanced dancers you alluded to. What is also true is that in a dance context, the inability to support the weight forward in the feet can often be caused by posture alignment problems. The common problem of leaving the hips behind in a forward movement is also often caused by some level of instinctual resistance to commiting to a forward movement when someone is standing directly in front of you, and may have nothing to do with inadequacies in the feet. The same people who might show this problem while dancing with a partner usually have no inadequacies committing their hips forward while walking.