I think "free jazz" was expressing a lot of anger. Even very late Coltrane, like Interstellar Regions and Ascension. They were also spiritual. I think it was the black man's attempt to "take jazz back" from all the people, cultures, and industries which had assimilated it, and transformed it into entertainment, and commodified it.
They wanted jazz to once again be the artistic expression of black Americans, and not the soundtrack for TV shows like Peter Gunn, Mannix, and Perry Mason.
John Watt, no harm done, riff on brother.