Prisoner's Island doesn't encourage reform, it just creates a cesspool that makes people do more of the same. People learn by example, so if you match 5 toxic people together, they just learn each others' bad habits and become worse and worse over time.
If you REALLY wanted to encourage reform, you'd actually match ragers with 4 people who all had honour ribbons so they could learn by example.
But that'd be punishing the honour ribbon people, so they wouldn't do that... so what they in stead do is provide a punishment system that teaches people what they've done wrong.
AFKs/Leaves are punished by being forced to lose their own time since they wasted others times(the leaverbuster system). Ragers are punished by being forced to watch what they speak(chat restrictions). And extremely escalated situations are simply removed from the pool(bans).
This is an educated approach to punishment. Whether I agree with the way they DETECT leaves or not, it is still a far better punishment system than simply putting people in a place where they constantly spiral downwards, written off as hopeless by the rest of the community.