Will you go back to management school?

Why is it that not a lot of people who take undergraduate management courses would want to study again after they've graduated?  Sure, a lot of them will say that they'd want to pursue further studies in the future: that is if you ask them while they're still in college and all they're exposed to are their books and their professors.  But what's the real count? How many really go back for further studies?

From my experience, unless their jobs (or pay) require an additional degree like an MBA, most will continue to go on with their professional careers. And I think this is not because they do not care to learn about management further.  Rather, I think it is precisely because they are learning more outside of educational facilities that they do not see the value of going back to school.  It is as if they have realized that real world competencies and knowledge that can be applied in the workplace are absent in the classroom.

I guess what I'm really thinking is this: if management education is of real value in the real world, why aren't many people re-investing after they've gone through it in college?  Have they learned all there is to learn?  Or is it simply just impractical and useless (read waste of time and money)?

(The experience is not the same especially in the field of ICT/IT, medicine, agriculture, and others in the field of science, etc., where people really seek out courses to learn further.  Can't management education be as practical and grounded?)