ORIGINAL: Missileman
Your mistake is making the assumption that we crash all of our airplanes. That is simply not true.
Yes we do crash from time to time but most of our airplanes will never suffer a crash. Many get traded away or retired somewhere in the back of the garage.
I have heard it said that all RC airplanes have an expiration date. I don't buy into that. If real airplanes were given the same mentality then man wouldn't bother to fly at all.
I crash a lot of my planes but it's because I constantly expand the envelope of flight. Sooner or later you (I) exceed what either the plane or I can handle. I have some long life planes too but if you don't push the envelope you don't learn as much IMO.
That said, I didn't push the envelope too far when flying full-scale due to not wanting to die. I did fly full-scale competition aerobatics but I did that with an appropriate plane and intense training.