Google, Yahoo, and Apple's purpose is to maximize shareholder value. Those other things are just marketing fluff. Yahoo could do with some better marketing.
"Maximize shareholder value" is not a company. A company needs vision, it needs to do something or build something. A company needs profit, and preferably lots of it, yes, but it also needs a guiding philosophy that informs the markets it enters and the ways it enters them. You can call it "marketing fluff", but it's what makes the company what it is. For the best companies, profit is part of the vision, but it does not subsume the vision.
Google and Apple are both very successful companies, but they're both very different. You can deride the difference between them as marketing fluff, but I call it "successfully executing on vision."
That's an incredibly reductionist view
Maybe with 2nd or 3rd generation leaders Google et al will be maximizing shareholder value for the sake of maximizing shareholder value. But not yet. They're still doing what their founders want them to do.
The mere pursuit of profit is always fatal in the long term because it's essentially a short-term outlook that leaves you rudderless.
Look at the car industry as an example. Toyota has been consistent in its pursuit of customer value, respect for staff, and waste reduction, with profit coming way down the list of priorities. GM, on the other hand, is where the modern increase-shareholder-value school of management originated. Toyota is now the world's largest car company, and GM would have died without a government bailout.