You do understand that market share is a percentage right ? It going down has no bearing on the health and growth of a company. It just means that the market is expending. That's the whole point. It's sad that people think you're not a healthy company because the market you play in suddenly has a wider audience while your niche remains.
RIM wasn't dying. The media however didn't make it sound like it. This drove investors away and with that, customers started being wary and left. Now they are having real problems, shipping less units, posting losses. But don't be fooled. It's the media game that did them in, not their actual health back when this all started.
That reminds me of another company some years ago—a company with a successful but ageing product. A diverging product category emerged and they had the first commercially successful product of its kind, but it took time for consumers to embrace this new technology. By the time others brought forth competing products, they were losing significant market share and soon became a niche player in the market. Year after year, numerous articles were written, countless predictions made of the company's impending demise. But through all this, they had a solid product, and many consumers stuck with them. You might have heard of this company and their product: Apple Computer Inc, and the Macintosh.
Surviving with a niche product is difficult in the PC market, not because consumers pay much attention to investor confidence, but for other reasons. For one, the viability of any hardware platform relies heavily on software, and developers are naturally going to be drawn to the most popular platform. Economies of scale disadvantage smaller players, affecting price. There's generally less word-of-mouth advertising, and other factors. The Mac's history shows that it is possible—but a genuinely compelling product is key.
Now, you're arguing that investor reaction to RIM's annual performance was in fact a self-fulfilling prophecy, and you're downplaying the fact that Apple released a damn fine product to market, closely followed by other companies. Many people were predicting the failure of the iPhone when it was first announced too. Remember that? And the iPod before it? Doomsday media predictions are nothing new, and they don't always prove to be a great predictor of what the market will do!