Whatever your opinion is of the guy, I remember Thomas Sowell talking about this exact phenomenon. He was arguing against having race quotas for ivy league schools, because often academically under qualified people end up floundering and failing in the environment, and it's really sad. He argues that many of those who fail under these circumstances would have thrived in a regular, less competitive 4-year school. You can't just throw someone into an ivy league school without prep, experience, and resources for help and expect them to succeed. The pipeline for getting ahead has to start way earlier so that I person is actually prepared and qualified.