Have Americans abandoned their cultural musical roots? Why don't they support jazz which is a true American art form/?

To be short, "abandoned" is an inaccuracy, although it's true Jazz hasn't hit the Top 40 in some time. There are many jazz enthusiast as evidenced by album sales of jazz favorites, inclusion of jazz standards reinterpreted by popu!as artists of today, jazz concerts in virtually every state and an online jazz community which spans the country and the globe.

Sidebar: American musical heritage and its roots did not start with jazz. Jazz has a predecessor. I say this to illustrate that neither music, language, law nor any other creation of man exists in a static, unchanging vaccum.

The hey dey of Jazz has passed and is as likely to reemerge as is the African work songs of the south, gospel spirituals or ragtime.

I often visit my favorite jazz songs on YouTube and it never fails to surprise me when I see the number of comments from young people exclaiming, "I'm 15 and I love this music!" How often does it happen? Very often :)

People do support it- as a historical art form because it's no longer something that can be called current or "popular". Just as there is a demand for people who can play Baroque musical instruments in the Baroque style there is a demand for people who can perform jazz. In every such case, the demand is going to be limited.

No, they haven't... At least you say something logical, and not something like "Icelanders created the word and musical form jazz".

Most people don't like Jazz and it barely qualifies as an art form.