there is an article here somewhere "why Harleys are not real motorcycles" that explains it all..
My personal comment on "hard-core-harley-riders-behavior" is as follows; a month ago, it just so happenned and I "blended-in" a group of Belgian Harley riders, completely unintentionally (actually, I was going slower than a fat lizard and STILL I had to be faster than them..) on the mountain roads of Delphi in Greece.. Seems the guys were looking for Delphi (the archaeological site) but passed over by mistake and were quite lost.. I approached what appeared to be the "leader" of the bunch (yes, they do have things like that..) and waved - nothing.. shouted "hello" - nothing.. lights, horn - nothing still.. finally, I shouted to him "IF YOU ARE LOOKING FOR DELPHI, IT'S BEHIND YOU!".. and he goes "hmm..".. I then go "are you from Belgium?" (I saw the plates..) and I got no reply.. They all stopped, turned their backs on me and started going the opposite direction. That's it, no thanks, no nothing.
I think this is crappy motorcycle behaviour, and I 've seen better from people driving just about anything that moves on the streets..
There HAS to be an ego problem coming "installed" in this motorcycle. Everything else is extra. Including good manners..