The reason it's saying this is there are nemerous security exploits for users running as root. That's one thing you don't want to be taken over. A single 'rm -rf /' (DON'T TYPE THAT!) can bring your system to it's knees within seconds, and only root can do that since it's deleting everything off your drive(s). Various permission controlled directories need to stay that way. Just make a user, and use the 'su' or 'sudo' command for doing your root work.