Help Me Out Here

The guns I get. The ammo, sure. And the speedloader, the mags, the black Speedo, even the odd discoloration on the upper thigh near the crotchular region. I get all that.
Why the Guitar Hero controllers?
WHY?

The guns I get. The ammo, sure. And the speedloader, the mags, the black Speedo, even the odd discoloration on the upper thigh near the crotchular region. I get all that.
Why the Guitar Hero controllers?
WHY?