I've had this debate many times. IMHO... The "BEST" team in the nation often isn't #1. I think Baylor is the best team but SC will stay at #1 until they lose, no matter what Baylor does. ASU started the season ranked 20/18 in the polls. 2 early losses dropped them down to about 32 or so.
They have since been climbing back. beating Oregon and OSU jumped them up something like 10 spots to #18, Absolutely fair for the RANKINGS. One could argue they are one of the top 5 teams in the nation. I disagree, but that's irrelevant for the rankings. They are exactly where they deserve to be based on 2 great wins.
I might have put them at #15, but with 11 weeks of hoops and 15-20 games for each team, NO ONE is going to jump from unranked to #1 unless they go on a 6 game win streak in April and win the NC.