One argument that I remember the people involved with Deep Space Nine made for why they didn't specifically address the normalcy of homosexuality and same-sex relationships when they did "Rejoined," and used a Trill taboo as a metaphor, is that by not specifying anything significant about same-sex relationships in depicting it is a statement in-and-of itself.
That, similar to how no one hardly ever acknowledges racial and gender differences because Star Trek exists in a future where humanity has overcome those social issues, the fact none of the characters think it strange, weird, or have a reaction to Dax considering a relationship with a woman speaks to the normalcy of a spectrum of sexuality in the 24th century, in the same way no one ever specifically is amazed by a Black man being the captain of a starship/space station or a woman being in charge of Voyager to point it out.
I do wonder if you could make the argument that maybe in the 23rd and 24th centuries the "flexibility" of sexual preferences may have expanded to the point that no one would be surprised by bisexuality? I do think the franchise overall usually assumes the heterosexuality of the characters (i.e., you never see an attractive man come on-board the Enterprise and any of the male characters show interest in a way that it has been implied to the female characters). I know Russell T. Davies made that a part of the Doctor Who universe with the Jack Harness character, where The Doctor specifically mentions that human culture in the future has become one where specific sexual preferences have become a more antiquated notion.
I do remember when Star Trek Beyond came out, and depicted the Kelvin Universe version of Sulu in a same-sex relationship, George Takei made news when he stated that he felt the TOS version of Sulu was straight because that's what Roddenberry intended and that's how he played the character.
I will give him this, JMS has never claimed Berman or Piller specifically knew or stole any B5 ideas with DS9.
"I have never, *ever* felt, or believed, or thought, that Berman or Pillar EVER saw or knew about the B5 information. Had anyone suggested anything of a less than straightforward nature, they would have refused; of that I have no doubt." (JMSNews 6/19/1995)
It's more of a general, well I had an idea to do the western first, but the other studio decided to do their own version of a western. I mean I can understand his frustration seeing his idea be rejected, and similar ideas used in something else imperiling your own show's viability, but you can't claim the entire space station genre any more than Star Trek can lay claim to every version of a "starship traveling in space" dramas.
Tough to argue with that logic.
