We played a pretty decent game but this poll must have missed the Sc Ohio state game.
First, it's not a poll, which means to me that some human makes a judgement, but a rating done by a computer program.
And it's an unbiased program, meaning it has no pre-programmed indication that Ohio State is any good based on reputation or previous seasons. Ohio State beat Ohio and Youngstown St, neither of which has won any other games. So to the program, with the limited information it has, beating Ohio State isn't much of an accomplishment.
As the season goes on, if Ohio State beats teams with winning records and wins most of its games, this will factor in as a bigger win.
USC also beat Virginia, which is only 1-1 in its other games.
Nebraska, on the other hand, beat SJ State and W Michigan, who won their other two games, and NM State in their only game. Nebraska is probably one of the few times to beat otherwise unbeaten teams, which is why this programs ranks them at #1.