So far, after looking at the Cal/UCLA 2015-16 transfer threads, I saw quite a few 4.0s that got rejected. I wanted to ask, why was this? I understand that a few more factors like Major prep and IGETC completion are also a large factor, but most of the 4.0s that I saw receive rejection also had those factors along with it. Not only that, these people also had a fair amount of E/Cs. It seems like it could be because of their major and if it's impacted or not, but even then, I saw a few non-impacted majors get denied.
All things aside, though, why are 4.0s rejected? What are some of the common reasons why they get rejected? What can those with a 4.0 do to further increase their admissions chances to these high-ranking UCs? I understand that a 4.0 GPA does not equal 100% guarantee, but I thought that GPA was one of the most important, defining factors among transfer admission. Not only that, a 4.0 applicant usually has those other defining factors (i.e. major prep) along with that GPA. Maybe I'm wrong, though?