TAM was about 2 things and 2 things alone. Bama's weakness in the defensive backfield and Bama coming out flat combined with a red-hot TAM team. Alabama is without a doubt a better team than the Aggies. Give them credit, they did what was necessary to win which is all that matters. However the reasons were emotional more than anything else.
I've said it here before and I'll say it again. Coach Saban's greatest weakness, really the only one I've detected is an inability to get teams emotionally prepared. What he and the staff have instituted in personal dev. terms is going to pay dividends in these players lives for decades, but there still remains stretches and games where Bama just isn't where they need to be emotionally considering the target they have on them every time out.