That is a solution to the disease that’s most prevalent in her world: the one that makes dead people get up and try to eat living people. Immobilize them by cutting off or destroying the brain, then destroy the diseased tissue. Which is a perfectly rational option when all you have are primitive methods for fighting disease because there are no such things as clean rooms or pressurized isolation rooms anymore, you can’t mass produce antibiotics and you can’t get to the drugs already available because getting to them means going through masses of dead people who want to eat you. She probably does know better. She’s working with what she has at her disposal. Still on Team Carol.