When a postal worker goes postal, it's going postal. When a PhD from Harvard -- the first detail mentioned, note -- goes postal, they are suffering in an academic pressure cooker. Dumbly applying the nearest pop-psych explanation to hand to explain the inexplicable only makes it more difficult to show respect for the victims and sympathy for the grieving.
I don't think the author was applying an explanation either dumbly or trying to reduce its significance. I think it is part of our human nature to try and contain a tragedy by labeling or attributing some cause to it. I'm not a therapist, but I sincerely believe this human trait persists in many people as a coping mechanism. That's why it makes sense (even as an academic myself) in some weird, comforting way.
Are you implying that tragedies have no cause.
It seems like human to try understand tragedies as they are significant part of our human world. Moreover, tragedies usually do have causes.
Claiming that there is no cause to an event may serve some psychological purpose...