I think a lot of it stems from the dorm-ification of workplaces. Because the ROI is so good, employers want you to think of work as more of an institution that is heavily tied to your identity rather than just a place of business. You're not an employee at Google - you're a Googler. Once you leave, you are a Google Alumni. The end result is that your whole self is brought into work because the boundaries between personal and professional life are heavily eroded.