The problem with charismatic leaders is they can start to believe their own hype, crush all dissent around them and then start to make mistakes.
We have seen this with several high profile Managing Partners and this article explains how it happens and why.
In most cases, charisma is a useful quality for CEOs. Many work hard to develop charismatic skills. Especially when an organization is asked to become more innovative and to perform beyond normal levels, having followers with an unusually strong belief in the leader and their vision increases the odds of success. But charisma has a dark side that can sap the strength and potency from an organization. If it grows too powerful, the leader becomes ineffective at motivating others and at driving the business.