Yamaha 4-Strokes; Why Rear Exit Exhaust?

Why do Yamaha 4-stroke sleds route their exhaust out the back? There are several benefits; the rear-exit exhaust is straight for maximum power. Handling is enhanced as the engine design is tipped back to centralize the mass, and the rear muffler location reduces front-end weight. Durability is also improved, as the rear-exit exhaust greatly reduces underhood temperatures.