While there's an element of vanity to them, I think selfies are harmless fun. I'm tired of seeing them flogged as a generational wedge issue. I take them rarely, primarily because I never look as good as the young women that make up most of the "selfie" demographic. It's a generational fad and will certainly be replaced by something that angers and frustrates the next generation's forebears even more.
I see the selfie as a confluence of several phenomena that are prevalent today. One is social isolation and disconnection. People are anxious for connection, and this is a method they use to relate to one another. Social groups are more distributed than any time in history, and viewers of the selfie get a feeling of participation in the subject's life.
The selfie is part of a diarist trend that became popular with the easy accessibility of the web. It must have started earlier than personal homepages, but that's the first time I remember encountering the idea of telling the world about yourself through the Internet.
I wish my family (going back several generations) had taken more photographs of the family as a unit, or as members. I look through an old photo album and skip right over the out-of-focus photos of the grand canyon and fixate on the ones of the people I remember and care about. I have access to the finest photographs ever taken of virtually any notable location on earth, and I can view them by the screenful in a matter of a second. Good photos are not a rare commodity, and mediocre ones are worthless. Photographs of myself, standing in front of the grand canyon are unique. My possessing a photograph of the canyon itself tells you nothing about my experience, as anyone can have one.
It's possible to take perfectly acceptable selfies and struggle to eek out a decent landscape photo. In fact, the cameras on most phones are a little bit wide simply to accommodate the use for selfies. The selfie is part of the democratization and de-skilling photography has undergone since digital photography became ubiquitous. Make twenty attempts at a decent selfie, keep one, it costs you nothing and you get the photos right away.
Another factor causing people to hold a phone out to arms length is the lack of trust in our society. While the numbers tell us we've gotten safer most anywhere in the U.S. (where I'm writing from) our trust has declined. Do we really feel comfortable handing a stranger our $800 phone full of our personal information so that they can take our portrait in front of some natural wonder? I know I don't. So the phone stays in the hand.
Like any shift in social behavior due to technology, it has its pros and cons. Selfies are one of the things I'm least concerned about.