It is no accident that expert performers spend hours practicing the fundamentals of their craft. Every day, NBA players shoot free throws, instrumentalists play their scales, and MLB players take batting practice. Science provides an explanation for why experts continue to drill their basics, and why dancers should as well.
Because the brain continually adapts through practice, the performance of any skill becomes more automatic. However, that automaticity comes at a cost: once a skill becomes automatic, the brain tends to pay less attention to the finer points of the action. Because the brain is less focused on the details of the skill, important details can be lost. An extreme example is the condition of focal hand dystonia, which afflicts some musicians. These musicians have practiced rapid coordinated hand movements to such an extent that their brains have actually remapped the areas associated with each finger into a single area, with the result that the musicians can no longer use their fingers independently!
Lots of WCS dancers experience this kind of automaticity in a milder form. If you have any habitual movements—maybe you always do a ronde an an anchor out of a tuck turn and struggle to do a regular anchor, or maybe you automatically do a kick ball change on the start of a new pattern—you are experiencing this kind of automaticity.
By going back to your basics, you can keep your habitual movements from taking over your dance. The Bare Bones Dance is an important practice tool precisely because it forces you to break your habitual movements and keep your dance fundamentals clean.