There are many influences that make people hand over cash for a Fuji X-Pro 1. There are those seeking lighter weight. Those looking for retro. Those perhaps even first time buyers seduced by good advertising. For a while in the media it was ‘the second camera to have’. the world and his brother seemed to have bought one.
My ‘main’ camera is a Nikon D800. It is now outdated and superseded by the D810; I don’t have any plan to update it in the next year and probably not the year after that. Along with the 16-35mm and the 70-200mm, I usually carry my 50mm lens. None of them heavyweight but together I know they are in the bag. For some years I carried a Nikon DX format camera when weight was critical.