As one of those big cam, ported heads, big compression guys, there's something you're missing. Power delivery of a high strung air cooled HD engine is reminiscent of a big block V8 from the 60's. My Buell reminds me of an equally as hopped up small block. Super high specific output 4cyl cars and turbo 6's are just different. They don't hammer like a stupid Harley does.
Having ridden a few Victory's and Indians, I can see why people like them, but they don't do it for me. We could talk ergos and quality feel, but those are subjective.
The new 8 valve Harley feels like the Indian Engine to me. Both are big inch, slow revving, shallow breathing powerplants. They make torque, but I can make torque with a breaker bar. That won't get me to 100mph. An engine that makes peak power at 3500rpm is totally useful for pulling trailers. That kind of power falls into the "no fun" area for me. Theyind me of a hopped up diesel truck. I get that a 900lb bike needs a truck engine, but I think a threshold has been crossed.
As to the why, well it's what I like. I like my FXR. I like riding it. I also like that I can beat up on liter bikes on the street. I'm not laying claim to lap times, but my lack of self preservation combined with a majority of the talent pool I encounter lets me use my piece of shit 1980's era Harley to leave many sport bikes in the dust on my local favorite roads. Is it trolling? You bet! Is it fun? It NEVER gets old.