My dearest mentor, a man who has forgotten more about *nix, coding, and about anything else than I will ever know has a HS diploma and can and does run rings around everyone else. He has a mind like a steel trap. All of the great coders I have known had, at best, a BS or BA, none of them in an actual IT discipline.
Anyone can learn to code, be a great sysadmin, or a network guru. All it takes is want power. If you want it bad enough, you will get there. In fact, I'll hire a person who has changed careers into IT who is smart and hungry over a simpering PhD candidate who thinks they are the cat's pajamas. There are some calls for PhDs, but not many. It's a badge of some sort for companies to show they have "smart" people. PhDs are great at research, not so much at actual doing things. This has been my experience with working with more than a few.