I guess it all comes down to whether ownership means that you own something. They own these birds, and they can do whatever they want with them. If you think that not flying them will save them, put your money where your mouth is and save a few...guess not. Were it not for the ability to fly these relics, they would have all ended up in the scrap bin. Very few people are willing to put the money into mothballing such things.
I seem to recall a whole hanger of historic airplanes getting trashed by the weather a few years back. And another hanger catching fire and clearing out another batch. Face it, no matter what you do, they won't last forever.
If you have to crash something, a P51D is a pretty good choice. Most are completely rebuilt from new manufactured parts. Every part you could want is available new, with the exception of the ID plate.
-Chuck