You're so right. Jazz musicians are boring. Worst than that, I hear them complain every time that "the crowd was not in it". So, they don't even try to be less boring, they blame their clients for it. Way to go jazzmen!
It is niche music, there is no doubt about it. The jazz festival circuit seems to be doing just fine, albeit, most of the popular festivals are outside of the US. Heck, most of the really good older jazz musicians moved to Europe 30 years ago, anyways.