Well, I assume we've all met people (particularly since this is a board nominally for entrepreneurship involving software) that did very well in school or in other activities where there is a very well-laid out set of steps to follow and flounder when responsible for picking what to work on. If cmu wants to have high-impact graduates, they may feel they have enough people who dot every i and cross every t and get perfect grades, and would like more of the people likely to be impactful in life.