The trend to moral progress has been one of less accepting of violence, [...] and less standing by while terrible things happen to others (or at least looking indignant at past instances of this).

I find this juxtaposition unintentionally hilarious. The reason modern society does so much looking indignant at past instances of terrible things happening to others, rather than stopping them while they are happening, is because the only way to stop them is to use violence oneself, which modern society is especially uncomfortable with.

In general this is the problem with attempting to blindly extrapolate present trends past the point where they come into conflict with other present trends.