In my case, for a child-like reason. I am of the age that when I was a kid, it was super-cool to attach playing cards to your Stringray bicycle with clothespins so you got that thwap, thwap, thwap noise from the spokes. Well, I never outgrew that and when I finally got my first Harley after having owned a Honda and then a Kawasaki, I put on some Vance and Hines slip-on mufflers and fired that bad boy up. Immediately, I was 12 again and had the same ear to ear smile on my face. Now, I know that reason alone doesn't make me a "Harley" guy but it was reason enough for me.