If a public company managed to lose half its market share in 10 years, something would be done about it. A shareholder revolt would likely prompt some sort of cleanout of the senior executive ranks. Management would know the company faced being taken over, sold, or broken up. Any company director in touch with reality would publicly acknowledge the parlous condition of the company, recognise that its existence, at least in its current form, was under threat, and commit to undertake a profound reflection on the company’s future.
A promise from management to tweak the company’s marketing and to just “do things better” in the hope of returning the company to its past glories of decades ago wouldn’t go very far in satisfying the demands of disgruntled shareholders and customers. In fact, such statements would reveal things were even worse than they looked because it would demonstrate the firm’s bosses didn’t have a plan.