How much are your private communications worth? How about your reputation? Your bank account? Your identity?
These days, unless you go to extraordinary lengths, nearly every piece of your personal and professional life goes through a cloud service. The risk of having important cloud credentials compromised is too great to rely on protecting them with nothing more than a password.
An attacker who can get access to an important cloud service, especially e-mail, can commit espionage or sabotage, or he can just wreak havoc.
The solution is to turn on two-factor authentication (2FA) for every crucial cloud service you use, especially those that are tied to business accounts.