This is the conventional wisdom in the "real world" as well. There is expected to be a big difference between getting an MBA straight out of undergrad, and getting one after a few years of business experience. On the other hand, this could just be an age bias, e.g., someone with more experience also happens to be older, but their "experience" might not have formed them into a competent manager or leader. In fact, it's actually a toss-up.
Mind you, somebody has to do the accounting. We still need clerks, though they have different titles now. I tend to see middle management as being largely an information processing task: Collecting, organizing, analyzing, and communicating information. The MBA's learn how to communicate in a more or less standardized way, like having a standard API for a computer program. I've been a middle manager, but do not have an MBA.
Where managers, including MBA's, tend to be weak, are in the areas of leadership and decision-making. You can put someone through business school, but it's a toss-up whether you can turn them into a leader.
Mind you, somebody has to do the accounting. We still need clerks, though they have different titles now. I tend to see middle management as being largely an information processing task: Collecting, organizing, analyzing, and communicating information. The MBA's learn how to communicate in a more or less standardized way, like having a standard API for a computer program. I've been a middle manager, but do not have an MBA.
Where managers, including MBA's, tend to be weak, are in the areas of leadership and decision-making. You can put someone through business school, but it's a toss-up whether you can turn them into a leader.