[ghaff]

There was a good piece on public apologies by the media critic of Time, James Poniewozik, before he went to the New York Times:

"Public apologies are different from, well, real ones. A real apology, between actual private humans, needs to demonstrate true remorse and learning on the part of the offender and needs to make the injured party feel better. But in a public apology, the apologizer, and maybe even the apologizee, is beside the point. The real point is the rest of us–the larger society, asserting the norms and changing boundaries of acceptable behavior… A calculated, self-interested apology at least tells the rest of the audience someone did something wrong, while the apologizer figures that out in his or her own time, if ever."

http://entertainment.time.com/2014/02/27/defense-of-the-fake...

On the other hand, there are situations where some group gets offended by some statement or action and the apologizer doesn't really get the offense, and neither do a lot of other rational people, but the easiest path forward is to express a lack of intent to offend without actually apologizing.