One offense of poor user account use is privilege creep. Think of it this way. If your computer was a house with locked doors, the superusers and admins have keys to every single door. If you or anyone else wanted to access rooms, you should not be allowed to, that is, privilege creep. Imagine you get hacked while using your admin or superuser account regularly. This is like a robber having a key to every single key in your house!
Check out some tips to prevent account privilege abuse in this link:
Tap the Least Privilege link above to learn more about it!