Because cars with rear-wheel drive not only don't torque steer (front wheels, upon hard acceleration, fighting the driver's navigating intentions), but have a more natural feeling both entering and leaving a turn.
Torque steer (the tendency of front-wheel drive cars to pull to the side upon acceleration) is a problem with the Beetle, especially when you have a heavy right foot like I do.
The signature piece in this car is the all-wheel-drive system, which can shunt most of the engine torque to the rear wheels as necessary and will direct more torque to the outside rear wheel in a corner to help null out understeer.