I'm conflicted. I wouldn't argue about aesthetics; after all, beauty is in the eye of the beholder. Bikes are wonderful examples of industrial design and verge on sculpture. But, bikes are designed as a means of transportation and their form and beauty are based on that function. Decorative aspects of bikes make them cool, but are secondary to transportation. So, it seems to me that an abandoned bike that inadvertently becomes part of the landscape has a certain evocative beauty, similar to all those paintings that depict old boats on beaches. However, purposely placing a bike as landscape art seems a bit artificial, like the follies of 18th century England. A folly was a "fake" building constructed as a landscape decoration with little or no practical purpose. They included items like mock Roman ruins, Chinese temples, and Egyptian pyramids. So, I guess what troubles me a little is reducing a potentially ridable bike to a piece of decoration. In the end, it's "different strokes for different blokes."
A word about the all-white bike pictured above: So called " ghost bikes" are commonly used as roadside memorials at spots where a cyclist was severely injured or killed.