Investors could start getting angry if they feel that Google is blowing large amounts of cash on endeavors that continue to fail. By doing it this way they get

Investors could start getting angry if they feel that Google is blowing large amounts of cash on endeavors that continue to fail. By doing it this way they get a major stake in the potential success of their spin-offs, but they are able to continue delivering profits rather than sinking cash in one black-hole big idea after another. It's probably a matter of walking the line between short-term value of the already successful business versus long-term but riskier value of the potential moonshots.