Modernism appears pretty consistently in minds as an amalgam of several philosophical notions: positivism, materialism, physicalism, nominalism, liberalism, moral and aesthetic relativism, and atheism. There may be others. If you come across a man who credits one of them, it is a pretty good bet that he credits all the others, too.
It is interesting that, on any one of those notions, there can be no such thing as moral culpability. Modernism then looks like a retreat from morality, and so from responsibility, on every philosophical front. Implicitly, modernism makes shame and guilt inapposite to reality. Shame and guilt are painful feelings, and it is pleasant to get out from under them, via the conviction that they simply don’t pertain to anything – particularly oneself, or one’s acts. That is why modernism is tempting; this might account for its memetic success.