Do we really want to allow all that power to be consolidated into company boards and executives?
Companies will want to continue exist and generate more profits for their owners, which means deploying new products - and these products might appear to be different but upon closer inspection they kind of make sense. Facebook is connecting everything (core product + whatsapp + the internet balloons etc.). Googles core business appears to be analyzing large, dynamic and complex datasets (the web, maps, their biotech research, self-driving cars).
Of course there are always outliers (Android), but companies go for profit. If they can incorporate something new they will.
Additionally OP alludes to a greater vision which a company may use to impact its decision making on new projects to pursue.
There is so much you can do to attract and keep your users engaged with Twitter's core business.
For the growth Twitter investors are looking, twitter needs to expand beyond its 140 character tweets and look for possible innovative ideas that can cultivate with its current infrastructure, data and talent.
Source: I was one of the developers of Jaiku, which had a very similar model.
now you have a bunch of investors who are upset that they invested in a company at a 16 billion dollar valuation that has jack diddly squat for income and has no promise of some magical "over the horizon" way to monetize