In my System it's so about control and procedure. If anyone could become a Butcher then you'd get sociopaths who get off on torture and humiliation. I understand that this is a fetish for some but it wouldn't fit in my canon.

Butcher candidates are selected by the System as children. You can't apply to be a Butcher. They are chosen because they meet the criteria of self control. The offer of not mandatory. Refusal is accepted without escalation.

If they do accept they become System property. Dangerous investments that are taught to kill Animals and butcher the remains.

Imagine such an individual being let out into society? They know how to kill, how to make it last, so the System doesn't risk creating serial killers.

They do not create families. They do not have children. This is explained during acquisition.