I don't think he's saying blitz every down, but I think there's a time and place to play aggressive and then take your foot off the pedal. Always playing with your foot off the pedal is not something you should do when you have an offense that can score points like the Pats. Why give the other team time to do what they want on offense while taken time off the clock? Giving teams long drives also can get the offense out of rhythm. You always know the defense is on the field for too long when you see Brady get up and start throwing the ball.
It would be nice to see the Pats blitz on a 3rd and long every once in a while to make the QB actually have to think and get rid of the ball instead of thinking about what's he going to do after the game and then throw it to the open guy. And this is not just the Pats, most NFL teams play defenses this way which is bizarre given how many mediocre QB's there are.