And why he didn't raise the saddle off the top tube. I must assume someone other than the former Olympian would have last ridden it as it appears in the photo.

As for why someone would put such a thing on ebay, we could probably all do our descendants a favor by doing likewise before they have to do it for us or sell our bikes for $10 each at estate sales. On the other hand, our procrastination could be seen as a favor to the younger contributors here.