Frankly, the whole ranking system is shyt. It's really impossible to know who is worthy. We could run through the Top 25 and find teams where we could ask, who the hell did they play?
So let's say OSU goes to play MSU and blasts them. According to the standard "how many ranked teams" argument we all make, that'd be a + for OSU. However, I could easily say, so what?
MSU beat OOC Western Michigan, South Florida, Youngstown State, and lost to Notre Dame. They played in the same weak Big 10. Why are they even #11? I'd speculate we could do that with a lot of teams. How do we prove they're a top 11 team in the country to this point? Most teams play nobody OOC and move up by winning in their conference, having a better shot if they finished strong the year before, so they start with a better ranking.
I really don't know if OSU (if they beat MSU) is one of the best two teams in the country. And I don't know if Auburn is either. This is why we need playoffs because a team like OSU shouldn't be denied a shot at a championship for doing everything right, but neither should Auburn, who might be the better team, despite having a hiccup in their season.
Also, some of those arguments you use to prove a point about USC are flawed. Example, you mention 2003 USC beating a Top 10 Auburn 23-0, but Auburn finished 8-5 and looks like unranked.