I'll try to sum all of this up...

Learning to use the rudder is important
Not using the rudder can and will get you into trouble especially when you go to scale airplanes like Mustangs, and especially Cubs as you MUST coordinate your turns with the rudder or you will snap out just doing a simple 45 degreee banked turn. A Cub will try to roll over on it's back everytime if you do not use the rudder.
When you move to taildraggers rudder control is a must
When you start swinging 16 inch props you will need to counteract torque with rudder.

You are already using the rudder during takeoff to keep the takeoff roll straight. The exception to this is a tri-gear plane with nose wheel steering, you still are using the rudder but to steer on the ground, if you are not trying to keep you takeoff roll straight and just letting the plane go wherever it wants then you need more training.

Now I am NOT saying this to pick on any one person but as an instructor I have seen/heard all of the above.

I have even lost students to other instructors that do not teach rudder control because "It's too hard", yes I have heard that. We do not require the training for the use of the rudder but I always try to get my students to learn it.

As Ken said, learning to use the rudder properly will always make yopu a much better and most of all safer pilot