A big part of the reason behind that is the minimum of upsets that occurred on Thursday, as well as the seeding of course. As fun as the wins by cinderella are when then happen, they make for less interesting (pre-game) matchups the next round(s). The only real upset from the first day was WKU over Illinois, and that sets up another matchup of mid-majors because they happened to be bracketed with Gonzaga.