This page on server hardening claims:


  Disabling the root account is necessary for security reasons.


Why is disabling the root account necessary for security reasons?

If you're not using Root, you're using sudo! Sudo is a great way to become root only when you need to.


Root is a giant target. What's root's username? Root! I'm so smart :)
Logging. Sudo has a greater command of audit logging (so that when someone uses sudo to do something silly, you can tattle on them to the central logging server). This is helpful for forensic analysis in some cases.
Granular permissions. Root is a Big Flippin' Hammer. Do not hand BFHs to your users. Sudo allows you to specify that a user can run update commands like aptitude without password, but everything is off limits! You can't do that with the BFH that is root. IT allows you the flexibility of sanctioning certain commands for users, but disallowing others. This allows you to build a security policy that does not require an administrator to physically log in to a machine every time a machine needs to be updated (or another menial task).
Idiot-proofing. Why do you not hand users a BFH? Because they're dumb. Why do I use sudo instead of root? I'm dumb. Dumb means mistakes, and mistakes mean security holes and sysadmin-issues. 

