If you really like 3D, go ahead and keep on training, check your plane also and ask for 3D flight instructor. I believe if others can do it you can do it also, it’s a matter of time. Also simulator helps.

About your question I think is because, it's an aircraft, look like an airplane but partially helicopter. People are normally tend to the real one... 3D is fun but sometimes it causes misunderstanding at the field when others are flying. I believe lack of coordination or communication to fellow flyers or a little respect may work. And lastly, pilots are scared at the flight line. 3D for airplane eliminates the foremost principles of flying which is aerodynamics. Airspeed is the primary reason why airplanes are safe in the sky.

There's nothing wrong with 3D if done properly, it's part of our hobby. Airplanes are build as the same aircraft but with different purpose and application...