Comic Strips

Which sort of implies it was a white people thing that was influenced by black culture but not when it was too black.

I can see why you might think that from reading about it in 2024 but I'd suggest to you that the tempo slowdown is the major factor. Ska is an uptempo party music. Rocksteady slowed the tempo down and Reggae generally kept the tempo at that slower pace.

Also there was a progression of people leaving skinhead for rock following more high energy bands like The Who and The Small Faces and going through the psychedelic changes into Rock at the end of the sixties.

The fans of ska had no problem with reggae, especially Bob Marley, who was collaborating with Mick Jagger in no time. It's just they'd moved on from skinhead because the scene had become much more associated with violence. There was also the very deliberate efforts of the National Front to recruit football supporters during the early 70s heyday of football hooliganism. A lot of the people that were into violence were attracted to the second wave of skinhead just as cultural changes to the music in Jamaica and the UK meant that a lot of the first wave were evolving into mods and then some of them hippies and eventually you see the emergence of street punk at the end of the 70s.

As for Rastafarianism, that was not at the time a dogmatic religion like Catholicism or the Moonies but arose out of cultural immersion and community practice in the places in Jamaica where most of its adherents lived. I don't think it is a matter of being too black, it's just that it's very specific to Jamaica and eventually the Jamaican diaspora.

Edit: It's no accident that the third wave of skinhead was kickstarted by Two Tone and was explicitly multi-racial and also that Two Tone harked back to uptempo ska.