You guys are missing the point, the pros ( and every one should ) use the clutch not just to start and stop or get an extra boost of power but more so to control when the rear tire is connected to the engine. So when skimming whoops they modulate the power to the wheel, when they need to shut down the power they feather the clutch. On starts they use the clutch, not the throttle, to keep driving hard without bringing the front end too high. They use the clutch for bike CONTROL. Thats why the go through them in a moto sometimes.