What strikes me as I watch it is that the people in those photos, the teenagers and young adults at least, are now the leaders. Back in those days, they protested useless wars, pollution, racism, and poverty. Now some of that same generation, in turn, are sending our kids into useless wars, and letting the polluters, the financiers, and pretty much anyone else with a big campaign contribution bleed us dry. Many more are happy to tell us that we should shut up and accept what's done, because that's the best we can do. Just like our parents did.
It's as though every generation needs to be reminded of how things were when they were young. (h/t Taylor Marsh)