We live in a mobile-first world. What have we learned from the security mishaps in the past few years?
The traditional thinking of having walls around everything, putting everything on your secure network, well that doesn't work anymore.
The reason people did that is because they don't have infinite budgets, and they said, "Okay, we need to focus on security. The logical place to focus security measures on is the network."
Google's philosophy is a bit different.