So the basis of that comment is from a table in the Official Guide to the MCAT Exam that shows the results of a survey sent to admissions committees regarding priorities for selection. Now I don't have the book in front of me which makes quoting it dubious at best, but the table breaks the information up by three levels of priority and public vs private. If I recall correctly, the progression of GPA is listed in the highest priority for public schools with cumulative being either middle to low priority, and private schools list progression as middle priority, but I forget how they look at cumulative. This is not to say that progression trumps a GPA in general, but it is viewed more highly. I have assumed that this has to do with growth, maturity, life experience, and avoiding applicants that have never experienced failure.