Answer: Core rigidity
Step-by-step explanation:
Core rigidity is the opposite side of a firm's core competencies and it is caused by a firm's prolonged overdependence on the advantages it possesses, such that it does not realize the need to change and also prepare for the future. It is when a company overrelies on any advantage it has for too long.
When this happens, the competitors of the firm with core rigidity continues to improve and hence have competitive advantage over the firm in the long run. This can be seen in the example of Clean Rinse Shampoo discussed on the question.