Why do light taildraggers swirl uncontrollably on runways in a simulator? When a pilot chooses to run at a speed way above its takeoff speed on the runway in a simulator without taking off, the plane begins to skid and spins 360 uncontrollably around the yaw axis, what is the cause?
A taildragger is more or less a shopping cart being pushed backwards, or a car driving fast in reverse.  It's dynamically unstable when rolling and wants very badly to switch ends, requiring constant input to the steering.