Alice and Joe Henderson were doing great stuff in the 70's together too.
Beyond the chaos of the late 60's era in jazz, there are a lot of new directions jazz has taken since then. Jazz doesn't stand still, and I think that is core to it's nature. If this guy was looking to continue second wave bop for all eternity, he should just throw on some Branford/Wynton Marsalis and pretend like the 60's never happened.
We also wouldn't expect any genre to stay in stasis forever. Fracturing isn't even a bad thing.
This is a good point. Country music is the most popular radio format in the country. Yet Carrie Underwood doesn't sound much like Loretta Lynn and one could easily like one but not the other. Yet the "real country is dead" narrative gets little airing compared to the way the analogous complaint about jazz does.
If this author wants to say "free jazz is not to my taste" or even "free jazz is too dissonant," you know, he's well within his rights to say so. But "John Coltrane singlehandedly killed jazz with A Love Supreme" seems like a thesis impossible to justify.