I GUARANTEE you it's because she doesn't want the "homer card" attached to her hence forth. She even talked about it in an interview I watched lately and she said in paraphrase: "I think I've been a bit more critical than I should have (on the Seahawks)" due to the nuance of having a favorite team yet trying not to show any bias being a national analyst. Being taken seriously is very important to her, especially since she is quite good at what she does.
We all know what she really thinks deep down.