mbas can go any number of directions, and while one clearly does not need an mba to be a good manager, most (actually all) mbas I know that did go into management are much better at it than the philosophy majors I know.
Edit: I also wanted to say that the management classes I did take were super interesting. Management 101 is more like a psychology class than I would have expected. Also, I'm pretty sure the author got an MBA between 2008 and 2010