I think the author confuses simple likability for charisma. Charismatic people generally have a lot of likability, but not all likable people are charismatic.

Charismatic people aren't just able to get people to like them, they are able to persuade people to adopt their viewpoint. When someone charismatic wants X to happen, you find yourself also wanting X to happen.

This distinction matters, because the easy path to likability is agreeability: simply do what the people around you want you to do. They'll all like you, which is definitely valuable. But it won't necessarily get you closer to your goals.

Charisma, which is a quite rare trait, has a special balance of likeability and dis-agreeability, where people will get on board with your plan and feel good doing it. It's the ability to increase their agreeability.