Life is cruel. It is folly to blame any individual for any of it. As Howard Jones says, "No one is to blame." But, you know, it's like sugar, that desire to place blame. It's subtly addictive. What else should our hearts want to do with the crushing burden of tragedy but seek a place to set it down, and leave it? However, that place must necessarily be the heart of another person, the blamed one.
So you see, the songs title is not a lament, as in, "aww, it's really unforntunate that No One is to Blame." Rather, I hear in it a command --or at least a reminder-- to stop blaming, to do what we can to cure the tragedies where we find them, but to restrain our retributive urges. Frenzied blame-placing is how tragedy begets tragedy. First, before you lock-up any priests, or execute any teenage murderers, or bomb any countries, first just stand still and take no action other than to feel what hurts, plumb the depths of your compassion, and cry.
There is a great deal more to do besides finding out who's fault everything is. The work of repairing what is wrong is more important than placing blame, but it is also a lot more difficult to do.
And besides, whether or not you find someplace to put the blame, it really doesn't matter. No one is to blame.