Well, technically, such people never existed, as SJW is merely a term of derision, and doesn’t actually describe any specific beliefs. But, presumably, you are using it the way it used today to imply some minority of people on the far left who get upset about everything and don’t even know what minorities really think.
But that isn’t the case here. “Code of Honor” was condemned as racist by nearly everyone. It wasn’t even just viewers: people in production hated it. The director, who made them all black in the first place, was fired halfway through. Worf does not appear in the episode, because Michael Dorn considered it too racist.
You just are apparently unaware of all the racist tropes it invokes. It’s not just the black chief kidnapping the white woman because he was obsessed with her, though that is part of it. The entire aesthetic is that of 1940s racist depictions of African tribes. The actors even have the East African accent–something Star Trek didn’t do.
The all-white away team have to figure out a way to deal with the savage black people, while respecting their “way of life.” Tar even has to admit she finds something attractive about the animalistic nature of the man.
The idea that some sort of barrier was broken is ridiculous. For one thing, there is the aforementioned Worf, a black actor playing a Klingon, a race that was, by the TNG era, now always portrayed as black. If, for some reason, you needed a species that was all one race, you already had one–not that making a race all into aliens is all that great.
But, more importantly, no one was clamoring for an all black race of aliens. That’s like saying you want an all female race of aliens. Black people have been fighting against segregation, not for it.
Of course, if they just happened to be black but otherwise were treated well, like the Klingons, I don’t think anyone would have objected. It was using the old racist stereotypes. I can imagine that a lot of people were unaware of them–I was when I first watched the episode. But now that I know about the stereotypes, it’s so obviously racist, it’s ridiculous anyone tries to argue otherwise.
I believe you are an SFDebris fan. Have you watched his three-part review of the episode? While it was not remotely the only flaw he discusses, even he talks about how racist it is. And he’s about as far from an SJW as you can get without actually becoming a racist.