[icanhackit]

to preserve the memory

And to elevate oneself socially based on select signalling of goods and services consumed, places visited and activities performed.

The photos will happily sit on a device, external storage or the printed page for occasional review but let's be honest here: it has less worth unless others see it. It's not the memory-trigger aspect that's so important but the feeling people get from knowing others are admiring what they're doing. The act is mostly for signalling.

Some people forget the era where you typically didn't have a camera everywhere you went, and when you did have a camera you were limited by the amount of film you had. I remember that time and have plenty of vivid memories from it thanks to carrying the best camera I've ever owned: my eyes.

the cost to the experience is minimal

For the people capturing the moment perhaps. In Versailles I was whacked in the head with a selfie stick by a pirouetting halfwit. People fumbling with their phones and selfie sticks aren't considerate of the people around them.

[Dylan16807]

People can be plenty inattentive and inconsiderate without a camera involved.

[icanhackit]

True but give them a smartphone or vanity-stick and they become weapons-grade nuisances. I wouldn't advocate banning those devices, I just wish people would be more considerate of others around them. The problem starts with the individual, and being considerate is something that can be learned.