I'm new to RC and am on my second kit. I did buy an ARF trainer to learn to fly. I built my 4 * as a second plane and am currently building a Top Flite Spitfire. I enjoy working through from concept to design and implementation of a modification or added details. I have lots to learn, and enjoy the learning. I already have a lineup of kits. A TF P-51B, 5 Royal/Marutaka kits A6M5, F4U, P-38, B-25, and Cessna Skymaster, and a 1/5 scale SBD-5 Dauntless from DP Systems. I've almost completed turning my garage into a workshop.
Building is the aspect of the RC hobby I enjoy most. I enjoy flying, but not as much as I enjoy building. Satisfaction is the main reason. Starting with a box of wood, and ending up with a completed plane that has a combination features and details that are unique, gives me lots of satisfaction.
I See ARFs having a place, in helping progress my flying skills, or even for sport flying. But flying an ARF warbird, to me, would be like taking a pay check and turning it into a paper airplane and playing with it for a while. It might be somewhat fun, but wouldn't provide me the satisfaction of building it myself. Once I have gained the skill, I'm sure that I'll find scratch building even more satisfying and enjoyable.

Scott