I'm a jazz bassist. The author seems to pit stereotype against stereotype. I can't fault his analysis of ragtime music, but he needn't paint me as an enemy. His description of jazz musicians and fans seems to be from a movie, not from real life.

I play in a large jazz enesmble. We tend to favor newer material when we can lay our hands on it. The musicians and audience members come from all walks of life, and at least according to my own impression, are generally a cheerful lot, just happy to be able to experience the music.