Old Indian once say "Offense sells tickets, defense wins championships"
Sure, you have to have both. But sound defense keeps your team in the game, controls field position, creates turnovers (which lead to more offensive possessions), helps control time of possession, and gives an offense, especially if it's struggling, an opportunity to win close games. Good defense is to football what Linus' security blanket is to him when Lucy gets mad because she can't get Schroeder's attention.
Sure, you have to have both. But sound defense keeps your team in the game, controls field position, creates turnovers (which lead to more offensive possessions), helps control time of possession, and gives an offense, especially if it's struggling, an opportunity to win close games. Good defense is to football what Linus' security blanket is to him when Lucy gets mad because she can't get Schroeder's attention.