Here is a great example from a buddy of mine (Ben from DigitIT) about why passwords are important.
As his blog post details he was called in when a client found their machines displaying a message asking for money to unencrypt their files. They had been infected with Ransomware. Why? Very poor passwords as the blog post notes.
End results? A complete reinstall and restore of the server from a known good point in time. After that how much do you figure using strong password is worth?