Here's my logic behind this. If they are mounted to the column, then lets say your bumming around and you take a sharp turn, changing gears will be impossible because your hands wont be over the paddles. You could slide your hands to the appropriate paddle, but then your letting go of the wheel. If they were however mounted to the wheel, then they are always under your finger tips. Personally I think mounting them to the column can be dangerous to you and the car.
That's why I don't like them there.
Andrew