So in general I agree, that there are better methods than punishment, but for some it works.
Humanism is a relativly new concept. One worth pursuing, but maybe not blinded by idealism.
I believe it is worth the effort
> It was rather the norm. The strong eat the weak.
There are a variety of reasons for this. Different reasons have different most effective solutions. If we choose as our general solution something that has narrow scope of significant positive effect and wide scope of moderate negative effect, I'd say we've chosen poorly as that will harm society as a whole rather than help it. Which is why the hard task of getting those numbers is worth it.
I prefer to mix sciences of dynamics with love and mindful design. I've had a nuff* of the narratives of static sciences. What happens when we allow for resident psychopaths to shamelessly and fearlessly be themselves? Is that something we even have examples of happening, particularly where the dominant culture was a peaceful one of equanimity, autonomy, and interdependence? If we (humanity) haven't conducted that natural experiment, I'd love to give it a shot & work with them to answer the question of how can a community change to include them.
* I propose the unit of "nuff" as a subjective metric of satisfaction. What I say is a nuff is a nuff for me and what you say is a nuff is a nuff for you.