I've seen some very low mile HD's on the market, I think from people who bought them as a status symbol.
Years ago I remember there was a letter to motorcycle consumer news complaining that they do a lot of articles on BMW, where they are a small % of motorcycle sales.
They replied, saying that although BMW is relatively small in the market, their survey showed a large percent of their subscribers ride BMW.
I think BMW owners and a big part of HD owners tend to be motorcycle enthusiasts, as opposed to casual riders.
Also most of their models are suitable for long rides- not many race replica and smaller around town type bikes.