His English writing skill might be very strong, but since he didn't do enough research on those schools, his strength didn't use on the target.
Another reason I guess was: after working in big 4 as a manager, he had couple of short period stay in some industry companies, which made his career progress unclear. Thus adcom might doubt whether he was sure about his career goal or not.
sdyx, coopers brother is in Olin right now, which is definitely a school favor old students. Others I could think of now include Wharton, Kellogg, Michigan and Duke.
Darden is used to be in the same league in my mind, but now I heard two people complained it switched its gear to favor young guns now. However, I could be wrong since it was relatively a small sample.