Close Enough for Jazz

I play in two community jazz bands, each of them composed primarily of non-career musicians (I dislike the term "amateur" for its implication of lack of skill). Many of the members also participate in other community bands and orchestras which rehearse and perform music of a more "legit" nature. The caliber of these musical organizations is quite high; whereas many community bands perform at a high school level, these groups rate alongside some of the best college bands and orchestras.

Why is it, then, that musicians who are otherwise quite capable and talented fail to perform jazz with the same attention they give to other (legit) music? I have a pet peeve about the lazy attitude with which jazz seems to be treated. I mean, there's no difference between the notes in a given key signature in jazz verses a classical work. It's true that swung eighth notes in jazz are not strictly timed, but that's no excuse for ignoring written rhythms - the basic divisions of the beat still apply in jazz as in classical. Jazz does employ some idiomatic rhythmic nomenclature, but a half note still has a definite length (and it's not longer than two beats, assuming a quarter-note-based meter). In the absence of written articulations in a swung jazz phrase, the convention is to play long (legato) eighths and short quarters but when articulations are given, they mean the same as they do everywhere else: a dot means "short", a line means "long", a slur means "connected".

Let's abolish the aphorism, "close enough for jazz."