When I read about residents who didn't have the "sense to evacuate", I think of the old people who couldn't drive. It's hard enough for some old people to get someone to ride them to the doctor, let alone getting someone to evacuate them when everyone's trying to save their own skin.
Actually I think there are a lot of reasons that older people don't evacuate. Some people mentioned pets ... but a lot of old people have no family, sometimes they are mentally impaired or have health issues.