I don't think it's the stock market. If anything, it's the CEO not focusing on making products that make people's lives better and instead focusing on what everyone else in SV (and the tech industry in general) is making.
And I am confused what Apple could be doing that the tech industry isn't already doing. There aren't many raw innovation areas to get into now. It's all about execution and innovation at the micro level.
For me Apple's foray into health e.g. Apple Watch, HealthKit, ResearchKit as well as their pretty amazing stance on encryption and privacy is absolutely about making people's lives better. It sure as hell isn't particularly profitable.