"Al, I respectfully submit that your friend is very egocentric. The beauty of a tree is inherent to the tree - not the creator or the tree. If everyone felt this way about bonsai, there would be no old specimens handed down from previous generations."
I have to agree, kind of. Such thinking discounts an enormous amount of very very nice trees that can be made into nicer trees by someone else. The beauty of a bonsai is 50 percent tree, 50 percent person. A nice piece of stock is a nice piece of stock, or even a "finished" bonsai, regardless of who's been there before. I think seeking personal validation through stock choice is a bit--well--strange.
Stock can be changed dramatically by the new owner, building on past work--or not.
"This person feels that if the raw stock was not initially styled by him, it is never really his."
Why limit yourself simply because you have to "own" an image that will change anyway? Would you refuse to own a house because you don't like the previous owner's taste in paint? If the house were nice enough and showed enough promise to fit your taste and the price was right, you'd buy it, and repaint it, wouldn't you?