I think he's saying that if you completely ignore the "natural" desire of some the victims for at least some punishment you will just end up with said victims taking justice into their own hands. So if you are so lenient to the point where a lot of victims & society in general start disregarding the justice system because they think its unjust, you could just end up with a lot of extra judicial revenge.

In a way I kind of agree. Because while yes the victims shouldn't have a say in what sentence or punishment a perpetrator gets, taking it to the extreme and just completely disregarding the other party's grievances is probably dangerous and undermines the justice system. If you get a lot of people feeling that there is no justice to be had from the system, you end up with a super dangerous situation & I know how deeply that feeling can erode the social fabric since it happened in my home country.