I tend to buy bikes that have a lot of Patina, perhaps not as much as the one in the lake that the OP posted, but I enjoy the restoration process as much as I do riding them. It depends entirely on the quality of the remaining finish as to whether I will respray or preserve... in all the bikes I have restored, it is about 50/50. I'd never destroy a beautiful old finish for a bit of patina, but if the finish is gone, a respray preserves the bike and gives it a new lease of life.