I guess if the games were decided by who has the better defensive ranking then the Patriots have lost. Sure, defense is important. Fortunately the totality of a team's ability to win is where the conversation ends. See the Patriots and their not so good defense of 2011 for example.
The Patriots are a team built to win using potent offense, adequate defense, solid STs and optimum mental preparation/execution. If their is a way to accurately rank teams based on all these ingredients? Give me that list and where the Patriots rank on it!