I have long held that there is a fundamental distinction between an explanation and an excuse. In my “back in my day” moments I tend to feel that the distinction has been lost somewhere along the line, and that knowing the explanation for someones actions is now generally considered to excuse those actions. I don’t think it should. As usual, Roger Zelazny can say it better than I can.

There is always a reason. Whenever anything has been mucked up, whenever anything outrageous happens, there is a reason for it. You still have a mucked-up, outrageous situation on your hands, however, and explaining it does not alleviate it one bit. If somebody does something really rotten, there is a reason for it. Learn it, if you care, and you learn why he is a son of a bitch. The fact is the thing that remains, though. [He] had acted. It changed nothing to run a posthumous psychoanalysis. Acts and their consequences are the things by which our fellow judge us. Anything else, and all that you get is a cheap feeling of moral superiority by thinking how you would have done something nicer if it had been you. So as for the rest, leave it to heaven. I’m not qualified.

Roger Zelazny, The Hand of Oberon