I think that's a pretty unfair statement for Ahn. She was pretty unstoppable until she hurt her ankle. You can't fault her for Stanford's loss to Florida in 2011 and her loss to USC in 2012 was only her third match of the year? If she is healthy, she'll own the No. 4 slot for sure. But that's a big "if", considering the past year.
IIRC (on my phone here) Ahn didn't play much in 2012 to begin with.