Theory is definately a manual for the practical but you really get an idea about what to do when you do it. Unless you walk and fall, you wouldn't know how to coordinate your feet and how to maintain your balance. 

In the world that we live in, knowledge is something that we develop the most in schools and colleges. Although most of the educational institutes are now progressing towards action based learning, majority of educational institutes in our country still heavily depend on theory. This has lead to degradation in the value of our education. So even if you have a bachelor's degree, you can't get a decent job. We're talking about a person who's around the age of 21 and has spent over 16 years constantly under academic training. Method of teaching in early of your life forms your concept of learning. And learning or acquiring knowledge is not something that is limited in textbook and grades. Which further deteriorates how we learn in our years after full time schooling. 

Now, even if the system is gradually changing. We need to add practical training to our schedule. Develop extra skills, take apprentice, handle finances and much more to enrich our knowledge. Because, what the they teach might be in their hands, but what we learn is in ours.