People were more aggressive and less risk adverse in the past, and not as self-absorbed, but for the most part were never willing to stand up for what was right. For example, when Thomas Paine was in prison in France, the founding fathers left him hung out to dry. Nobody stood up to stop the genocide against Native Americans. There was a regional power struggle between the north and south US, which had different cultures, but poor southern white men did essentially nothing to help black men. America fought Germany because Germany declared war on the US, not because they were willing to fight Fascism, and the US did very little to help Jews escape. America fought Japan because they were pissed about Peal Harbor, not because of what Japan was doing in China. Very much of the domestic opposition to the war in Vietnam came from people who wanted to stay home, enjoy benefits of birth control pills, penicillin, and smoke weed, not because they had a more principled objection. I could go on.
I think its possible to understand a lot about "why this is", but we've got to be willing to give up our own vanity, and face the possibility that our ideals not only will not but can not be realized in anything like the form and time-frame that we may have hoped for. Our problems go very, very deep, its not like humanity just went off the tracks a few decades ago or even a few thousand years ago. Study animal behavior closely and you'll see that its all fucked up to, in pretty much the same ways. Maintaining idealism in the face of this takes an incredible patience, and a kind of courage. If we value courage, here's something to prove ourselves on maybe.