Michel, fair questions. Not everything that can be measured matters, and not everything that matters can be measured. But, I agree, a significant part of my comment was based on my opinion, not on hard scientific facts, but it is informed opinion after many years in business and many years observing Apple and Jobs.
The beginning of a decline, and the loss of momentum is pretty factual. Have you read AAPLs 10K? Sales for all their key products are declining, including the iPhone. You can even see it in most charts in the original article. The last two bars are heading down, not up.
My comment about innovation drying up is not as factual, but is also based in facts: there is nothing really innovative in the latest two generations of the iPhone, with Samsung and Microsoft ahead with better cameras, USB-C, wireles charging and other important features. The fact that fewer people are buying iPhones and Apple products in general, is also an indication that customers are not finding enough innovations to justify replacing their existing iPhones with newer models. I also mentioned the iPad Pro is a copy of the Surface, this is a pretty factual observation, evident to anyone paying attention.
Last, the comment that a company continues its momentum and trajectory after a few years after a leadership change is also based on facts. Especially when companies are doing well and the intention is to continue the course. Look at history, research, or simply observe the lag between change in leadership and a change in trajectory in F500 companies after a new CEO comes in.
One fact as an example: Louis V. Gerstner’s turnaround of IBM is one of the most celebrated in the history of business. It took over three years (April 1993 to October 1996) for IBM’s stock to breach the 10 year pre-Gerstner’s average. In the case of Alan Mulally’s turnaround at Ford, it was over three years to get the stock back to where it was the day he was hired.