I can't help but feel that these people will someday look back and have great pictures of these events but no memory of them.
Not necessarily. I am going to a lot of concerts (~3-4 per month), and I take pictures with my phone because of my horrible memory.
If stumble upon the photo a few months later, it triggers most of my memories and experiences, but without this sort of "evidence" I'd be totally lost on the details from that evening.
edit: And, after all, wasn't that kind of the original purpose for a photograph? To capture an awesome moment you want to memorize?