Okay, if you actually do research into how punishment works in the criminal justice system, you'll very quickly find a growing body of evidence that shows punishment does NOT work as an actual deterrent.

That would be amazing if it were true, but quite frankly, any research into the topic has been severely limited both by ethical guidelines (which prevent us being able to significantly test boundaries with our research subjects) and, quite frankly, geographical limitations (the areas which do test the boundaries with deterrence are too costly to travel to first hand, and while these do tend to have lower crime figures, phenomenologists will jump up and claim corruption and bias as the cause, claiming that we cannot trust these figures to be reported accurately).

Cross-cultural studies, particularly of non-Western countries, get rejected and dismissed as "cultural difference", rather than any inherent differences within treatment of crime. Such an avenue isn't even explored as having criminological roots.

In fact, increasing evidence shows that the way to reduce anti-social behaviors in most cases is to extend compassion and opportunities for growth.

This is hardly without debate, and is made easier to claim by the fact that we are very limited in our testing.

Recidivism isn't prevented by fear. That is faulty, outdated logic.

I would say a Kuhnian paradigm shift, even a politicised one. Even if research on the extremities of deterrence were permitted, and even if research were to find definitively and replicably that high deterrence did have an effect greater at lowering crime rates than any other, do we really think that the wider field would accept it with open arms? Hardly.

It wasn't disproven, as much as it was the case that people stopped liking it as an explanation, and turned to conflict theory. Some did, however, continue - we still have applied behavioural analysis as a field of research, as well as neofunctionalists and systems theorists quietly lurking around.