Smooth jazz is still a very alive genre of music. I know someone who operates a small-powered radio station that programs smooth jazz during certain dayparts. They receive an abundance of new music from artists. Watercolors on Sirius/XM is one of the top channels. "Smooth Jazz Internet Radio" is a top-searched term on Google. Berks Jazz Fest in Reading sells out almost all their concerts every year. You're catching my drift. The genre is alive and well and not really an aging problem. Go to Berks Jazz Fest and you'll see as many 20-somethings as 60-somethings. It's just not a profitable format on terrestrial radio anymore for various reasons. Saying that smooth jazz is dead is like saying that metal is dead or dance is dead. They're not. They just don't work on FM radio.
To start, Smooth Jazz is not the same as Jazz.
The Berks Festival is not a smooth jazz event... it is mostly real jazz with a hint of r&b.
Smooth jazz, as I heard one consultant describe it back in the late 80's, is "beautiful music for yuppies". Or, as Mike McVay said back then, "songs you've never heard by artists you've never heard of".
The term "smooth jazz" came from a listener to a demo tape in Chicago, also in the late 80's. She heard the music, did not recognize anything, but when asked how she would describe it, said, "it's sortta' like smooth jazz". The term was used by WNUA in Chicago, and then got adopted by the industry after R&R's effort to call it NAC, New Adult Contemporary, did not stick.
And you would be surprised that the formats that get the most listening by satellite subscribers are, for the most part, the same ones that get FM music listening. The only difference is in programming suitable mostly for seniors, where the 50's channel, the 60's channel and things like Watercolors and Beautiful Music get traction.
I began my career at an all jazz station, WCUY in Cleveland, and I find it almost offensive to compare the style of Kenny G with Ornette Coleman or Miles Davis.