Or maybe because he played in the late 1930's, and there are barely any people alive who saw him play. Kinnick was 30 years before anyone who played on that list, and football in the 30's barely resembles the game played today.
Throwing Kinnick on this list is slighty unfair because after college he enlisted and was shot down in the Pacific. Fighting for your country trumps anything a Pro football player will ever accomplish.