Post-Apocalyptic scenario, the government is gone.
A scientist finished his greatest creation ever. A self-replicating nanobot swarm that, when dispersed in the upper atmosphere, will settle in every living creature and estabilish a self-perpetuating network for data and energy transfer.
The nanobots inside a person shall interface with the brain, and help the person develop, for the lack of a better word, superpowers.
For animals, it just enhances their physical bodies and helps them fight disease and heal injury.
The way they are programmed to interact with humans is to let the person select a "Class" like in the good old Pen & Paper RPG games of yore. They can select a Class from among those programmed into the nanobots.
The person will be asked to sign a EULA and opt-in into the System. If they refuse, the nanobots inside the person will deactivate, their inert hulls create a chemical marker to let other active nanobots that enter their body know not to interfere with this person's physiology.
From the moment the EULA is accepted, they will let the person gain "levels" and "skills" by redirecting the neural and physical pathways of the body, enhancing the person.
Many blanks exist in this setting, but this Question in particular is about the selection of Classes.
The scientist is not mad. The selection of "Classes" and "Skills" were carefully curated to help people rebuild the world.
Assume he is perfectly rational and can preview many scenarios, or simulate them with A.I. help.
How would criminal classes help rebuild the world? Is it not better to just not have them altogether?
I mean purely criminal classes with no other purpose. Of course anyone with any Class or even without one can be a criminal, but they would have to commit their crimes without System assistance.
For example, "Thief" ( as in a Class that unlawfully deprives people of their lawful property), "Assassin" (as in a Class whose sole focus is murdering people), "Terrorist" (focus on civilian casualties and property damage), and so on?
I'm not talking about Classes that may cause harm but can be deemed necessary to the working of an advanced society, like "Soldier", "Spy", "Scout", "Trapmaker", etc. Just purely criminal classes.
It's okay to elaborate an answer challenging the assumption that he would introduce criminal classes to the "System".