The beauty of chopping up a survivor is it frees up good quality spare bits that can be sold of to a) finance a project and b) allow someone else to bring their restoration project to completion.
If everyone restored and maintained the survivors out there, it would be next to impossible to find a nice original exhaust, tank, seat etc. for sale.
And all the 1950's, 60's, 70's era cafe racers, choppers, race bikes etc. were at the time brand-new. Is it a crime to modify a brand new bike?
The idea of a true survivor is as appealing to me as anyone. I have a 1975 BMW R75/6 that is like it came from the factory. Was in storage at a dealer for 20 years and has 36,000 miles on it. Original everything, no dings, no rust, perfect paint. While I have no plans on modifying it, it would make a LOT of people very happy if I was to sell off the tank, sidecovers, seat, wheels etc. and it would make me a LOT of $$$.