A rider who cannot whip the bike is committed to land in the spot that is predetermined by drawing a straight line through the frame of the bike itself and to the other side of the ramp.  This rider can land short  (or long) on his line but can never change "the line" he is stuck on.  It predicts his landing spot (and hitting the ramp at an angle changes nothing.  you are still a slave to the "the straight line" you have chosen.)  When you can "whip the bike" the ramp becomes another course correction opportunity.  As your bike begins to feel the pressure of the ramp the advanced rider can steer aggressively on the ramp and actually leave the ramp in a turning arc.  The "whip" you see in mid air is the leftover energies from the maneuver being dissipated in mid air (as the bike goes tangent to its arc once again and returns to a straight line flight) .  But the course correction has already been made and the new landing spot is his.  Also remember that almost all ramps have perfectly smooth faces (no ruts) and are usually dry.  What better place to execute a turn than on a smooth, dry piece of track that as a bonus has your bike under a positive gravitational G force?   The rider who can whip his bike has a lot more turning opportunities on the track than the rider who doesn't.