You're connecting the different parts of that person's life without his consent. That is functionally equivalent to telling the parents of a closeted homosexual that he's gay, just because he publicly announced it down at the Manhole. People sometimes wish to present different facades to different people. If you allow for closeted gays, you must logically also allow for CEOs that hold personal opinions contrary to their corporate policy.

There are legitimate reasons why someone would like to compartmentalize different areas of his life.

A doctor might be expected to wash his hands between every patient, but also choose to pick his nose before preparing his own dinner. When the superfluous lab coat comes off, my professional expectations of him as a physician end.

We have done this for centuries, with tokens of office and traditional garb. Kings have their crowns, Popes their grand miters. Judges don robes, and sometimes wigs. Cops wear badges.

Facebook does not allow for this. If you add your boss as a friend, he is connected to your everything. You have to work to separate him from your real friends. If, on the other hand, he were connected to your "corporate peon" role, you could switch him on and off at the... drop of a hat. In fact, he could give you that hat when you get hired, already connected to everyone else in your office. And if you leave that job, you both burn that hat, and he gives one just like it to the next guy.

It is a good thing.