Before the advent of smartphones, you had a limited number of available shots on your camera. But now, people just photograph everything, without taking a beat of time to LOOK at what they are taking a picture of.
Why do they do that? They must end up with loads of boring photos, and no memories of what they have seen.
And, as a fellow tourist, you end up constantly getting in the way.(not that I care).
(this is after visiting Westminster Abbey yesterday).