To gain additional knowledge and way of thought in a structured and directed way, I presume. Networking too.
Why are you so dismissive and angry about that topic?
Tell me you went to a business school without telling me you went to a business school.
I didn't go to business school, but I understand the value of structured learning vs non-structured learning. I say this as someone who has gone through the unpleasure of the unstructured path to get to my current self.