Defense isn't just for sports. It also works for comfy furnishings.
A solid defensive line can be an effective way to keep a few teammates up front while having a respectable number of people on defense. It lets you easily focus on the goal before you while keeping the goal behind you protected. In furniture terms, this means you've got a comfortable zone of protection that keeps stains and spills off your furniture.
That having been said, this particular defensive ploy isn't going to stop a strong forward push from a bunch of big guys with beards and "ALL GET CRUSHED" tattoos on their shoulders. But it'll certainly let them be comfortable when it's time to sit down and enjoy the game. Don't they look so happy with their nachos and their chili dogs? Awww. Number 17 is even coloring a picture of his favorite quarterback. SO CUTE