I'm not sure why you think this. Is it because Harvard isn't in the list? UCSF and Columbia are two of the top IM residencies, and Emory is no slouch either (and was chosen partly for geographic reasons, per my understanding). Duke is an excellent place for anesthesiology and my understanding is that it will let my classmate do a significant amount of research. Not sure about the Neurosurgery match at Vanderbilt--may have been in part for personal reasons, but then again NS is competitive anywhere. I personally don't know much about that particular program.
For me, UCLA was my top choice for a variety of reasons, which I won't get into here. Suffice it to say, I felt heavily recruited at many of the other top programs in the country (including Partners, Columbia, UCSF, Stanford, etc). UCLA has an outstanding combination of clinical training and flexibility for research time, the perfect combination for a physician-scientist! I couldn't be more thrilled at my match results.
When the time comes, you'll hopefully see that there is much more to the match than pure academic reputation. There are a variety of places available and the goal is really to find where you will fit best and be the most likely to succeed.