Given the massive cost of truly repairing any rust today, I'm not sure repainting any car is worth the money unless it's a collector vehicle of some kind.
Years ago I was on a cut-line road with the Forester and tore off one of the rubber fender liners that protects the inside lip of the right rear fender. I didn't notice for a long time, and after I did, I never bothered replacing it. Well, today, that q-panel is rusting. However, no way I'd spend $1 on it. The car has close to 300K on it, and the small amount of rust is purely cosmetic. The several thousand dollars in a proper repair would be money flushed.
That said, premature rust can kill the resale value of a car. Personally I wouldn't touch a used Mazda right now, and the rust problem is becoming known among the general public.