The discussion is that generally very good teams do and should(in the game) beat lesser rated(per the rating in the game) or less talented teams. Generally the better or more highly rated team does and will outplay the lesser team. That’s what probably happens 9 out of 10 times when Vanderbilt plays Alabama in the real world.
What you’re referencing is called an outlier. Thats when Vanderbilt beats Alabama. It’s awesome and what makes college football very fun. Today, in real life college football, Vanderbilt made enough plays to win. It’s the 1 in 10.
The discussion here is that the outliers in the game seem a bit tilted in that bad teams can hang with good teams more often than some people might find desirable or realistic.
Literally - literally - no one has said that Alabama never should or could lose to a Vanderbilt.