We know how to treat rational people. Take for example a rational criminal, that is, a thief, a pickpocket, or someone like that who does engage in crimes, for certain reckonable benefit. We always look carefully at the crime, examine the evidence, and mete out to the guilty, the most appropriate punishment.
But, think of an irrational criminal. Depending on the criminal's (irrational) excuse, whatever reaction the society may show, will vary. Mostly that will be some sort of approval, but sometimes may even amount to half hearted opposition if the said act is unmistakably dangerous to others. In case the excuse borders on things like religion, one can be sure of support, whatever may be the heinous acts one wishes to do, from some part of the society.
We just don't register any act as a crime, as long as it is irrational in nature.
Why don't we consider irrational crimes as crimes? Simple, anything irrational, benefits us a lot more!
But why have we left it so? And why we are yet not in realization of this. Also of other beings, who indulge in unregulated fights for rational reasons like food or mate, but move in unison for all other things. Are other beings quite clear about this?