you definitely don’t have the authority to say he’s definitely beyond ANY help. That’s the part I find ridiculous, not the part where you think there’s something wrong with him

It’s an approach known as perpetrator type theory (or “Tätertypenlehre” in German) that was notably deployed by the Nazis to be able to punish people they didn’t like much harder than others, by allowing them to say for example that someone was inherently and unchangeably a murderer and should thus be executed. The crime was essentially just proof of that, what you got punished for, was what some judge deemed to be the innate criminal personality you had. In particular this allowed to hand out lighter sentences to “Arians” and to decide that Jews for example were inherently bad and could thus be punished much harsher for the same crime.