Studies like this, Draugnar, *indicate* things and *prove* nothing, this I know well being a skeptic, but, at the same time, they do tell us things that are in general true in the practical world.
Are you aware of the concept of "returning to the mean"?
It goes like this: we tend to think reprimanding people after they fuck up royally makes them shape up. Why? Because they were returning to the mean. Fucking up was an anomaly. And whether you scolded them or not, they were going to go back to their average level of behavior pretty quick, probabilistically speaking. But you attribute your scolding as the cause for what you perceive as a behavior improvement.
Extend that to the deterrent effect and you have a fallacy on your hands. That's more my opinion though.
But back to why all people are equally worthy - for all intents and purposes, we humans are all mostly alike. We have the same *types* of experiences and emotions. We make quite a large deal out of the differences (race anyone?) but really, being human is a pretty relatable thing if you are human too. We have a lot in common just by being people.
So in the sense that I can pretty well see myself being anyone who is a human being, and in the sense that I would not want myself to be treated like shit or devalued or told someone else is more worthy than I am, I do not do this to other people, because, you know, the Golden Rule.
Also, since a person could change at any time, and become anyone, you can never say that so and so is of such and such a worth based on their actions.
Osama bin Laden, yes The Devil Himself, the Enemy of Truth, Justice, and the American Way could have changed. He could have become Nelson Fucking Mandela. He didn't, cause, you know, he got shot. But he could have.
And he should have been afforded the chance, by, you know, not killing him. Capturing him instead.
Don't get hung up on the specifics of the OBL case please, it's an example.