This is a vastly oversimplified conclusion that only serves the author's interests. Of course he's going to say the MBA degree is worthless unless it's from Wharton... he went to Wharton.
A recent survey of top MBA students found that 88% of graduates say they were happy with the investment they made. Having come from a school that's not in the so-called top 5 (more like top 10), the MBA has opened so many more doors and offered opportunities I never would have without a degree.