They'd been tossing with being evil for a while, but I feel like Google Plus was their New Coke moment, where they momentarily went too far, then backed off to the "classic" Google, while secretly replacing sucrose with the worse testing fructose.

Before then, Google was an advertising company with a bunch of side projects to increase user interaction, so advertisers has somewhere to show ads.

Since then, every part of Google has been working to lock in the user base while trying to extract as much as possible from them.