Both have merit. I am so incredibly fortunate that in two of the things I spend most of my time on, engineering and running, I have had both a strong formal education and significant experience. It gives me an exciting perspective on what I do.
To give two examples from running, a person can read about running and workouts and efforts and intensities, but the first time you run lactate threshold and really really feel that you are at the right pace and you understand why it is an important pace, it will blow your mind! September 2007 for me. Second, after wondering why I had injury after injury over three years I tried a radical approach I had heard about, a low heeled shoe, with not enough support for my pronation, at least many shoe salesmen would tell me. Three and a half years later the only significant issue I have had was tendonitis, and that was because I wasn't doing the foot exercises I need to do weekly. In both cases the education combined with the experience made the difference.
So often we feel we can be an expert by reading an article about something. I am chief of the guilty in that case. Alternatively, we think, this has worked in the past, I know what I'm doing. Again I have made that mistake. It is amazing how close to failure something can be time and again and we still have a false sense of security or at least durability when a seemingly minor factor changes.
The point is, they both have value. As my alma mater WPI says, "Lehr und Kunst" which is German for Theory and Practice. Neither one can exist in a vacuum.