Its also a music education thing, they don't know the differences between 2 genres like jazz and blues. People don't see that jazz music is based on complex modal changes and intricate chord patterns whereas blues for the most part is a lot more basic like minor penatatonic scales and 12 bar blues.
Even the differences between Be-Bop and Hard-Bop are hard to describe if you don't play and instrument. When you listen to hard bop without this knowledge it doesn't dawn on you that the differences are melody based passages as apposed to chordal based music.
No offense intended but it the kind of nit picking you've outlined above that turns so many people off to jazz. I realize that I am equally guilty of the same offense with several of my own posts. For me it's less about the sub-genres within jazz as opposed to the general lumping of anything slightly "jazzy" into the jazz category. For example this thread should be highlighting many of the fabulous young jazz musicians making great music but instead we get lots and lots of mentions of vocalists, jazz or otherwise.
But enough bitching about it. Here is a video to one of the best young groups in jazz today: Mostly Other People Do the Killing - this quintet is the real deal and every one of their recordings is better than their previous recording. Highly recommended. Please give them a good listen.
I am into Jazz big time, all kinds of stuff as long it not electronic and not too free. From Coltrane, Davis, Jarrett, Lloyd, Monk, Barber, Fitzgerald, Holiday...and also some Krall, it all depends on the mood. Unfortunately I have never had any musical education. There was only an art teacher at school no musical educator. Even though I may miss the ability to recognize certain structures by name, it does not really take anything away from my enjoyment of the music itself. Especially in live concerts when the close interaction between the musicians and the visual component seeing them communicate just with looks or facial expression or just a broad smile before they "take off".
Seeing folks like Geri Allen & Ravi Coltrane at the Village Vanguard sitting directly at the edge of the stage is just &$?#ing great .