Narcissism is generally understood to be an excessive love of oneself. I would argue that the vast majority of those who take selfies don't fit that criteria.
The fact that "self" is in the name of the term doesn't mean it's bad. "Self-care" is a thing, too, where "self" is part of the term, but anyone with any sense at all agrees that self-care is a very good and very important thing. "Selfie," as a term, does not include any sort of value judgment. It's a neutral word. It is not equivalent to selfish, self-obsessed, or anything else. It's just a term for a person taking a photo of themself. Which is something that's been going on for almost as long as cameras have existed. And before that, self-portraits were a thing, too. Before phones with cameras were so ubiquitous, people would get friends to take pictures of them, or they'd go to portrait studios. Before cameras existed, people would pay to have portraits painted. Selfies are by no stretch out of the ordinary. The only difference is the ease with which people can take selfies, and the resulting control it gives them over how the pictures turn out.
Selfies are fine. Selfies are very often a way for people who struggle with self-image to be able to be more comfortable with their appearances. The popularity of selfies also makes it something that people can actually bond over. Right now, on Twitter,
#LGBTbabes is trending. LGBT people are posting selfies of themselves looking like babes. And the same people posting the selfies are also going through the tag and showering love on other people for their selfies. It's a declaration of unity and appreciation. And it's
fun. Selfies are fun to do. It's something fun that young people, especially young women, like doing to feel good about themselves and to feel connected to the people they share the selfies with.
And then people jump on them, try to shame them, tell them that liking how they look makes them self-obsessed narcissists. And it's bullshit. What's wrong with just letting people be goddamn happy? People always hate young people for wanting to be people. People always hate the things that make young people happy. That shit needs to stop. Young people are great, and they deserve to be allowed to love things, and love themselves, without miserable old bastards trying to argue they should feel bad about it. If some girl posts two dozen selfies a day? More power to her. If a tween girl like some shitty pop singer? Rock on, girl. If teen girls obsess over poorly-written vampire romance books? I totally ship the protagonist with the bad boy vampire. No shame. Only love.
And on banning people from criticizing, well, if someone is trying to shame a person for their appearance, or to shame them for posting a selfie, then that someone is an enormous prick and deserves to be shamed in response.