[yorwba]

Have you ever convinced someone to do something which turned out to be a bad idea? Charisma is a social amplifier. If what it is amplifying isn't good enough, more charisma only hurts instead of helping.

Essentially, you need just enough charisma to avoid being steamrolled by others when you're right and they are not, while not having enough to steamroll them when it's the other way around.