This is from a 2011 interview where they asked him about gay characters.Berman has been very quiet over the years since leaving Trek. I imagine a book or podcast or something would be fascinating and full of rebuttals for these accusations as well as reasons why certain choices were made.
Why were there no gay characters on TNG, DS9, Voyager or Enterprise? Was that your decision or the studio’s?
Berman: It was not the studio’s decision. I know that when Gene (Roddenberry) was alive he was very ambiguous about the idea of a gay character or gay characters on the show. He felt it was the right thing to do, but never quite had any idea of how he was going to do it. As Michael Piller had said many times, the idea of seeing two men or two women in Ten-Forward holding hands was not really going to be an effective way of dealing with it. So Gene basically didn’t do anything about it, and then when Michael and I were involved with the concepts of the stories on the show, we just felt it would be better to deal with concepts of prejudice against homosexuality and topics like AIDS metaphorically, in ways other than human gays on board the ship. So we developed a number of different stories that dealt with same-sex relationships, that dealt with metaphorical diseases that were similar to AIDS. But they were all done in alien fashion to try to get people to think about these things as opposed to just hitting it right on the head, which would be having a gay character on the ship. It’s something that Michael and I discussed. It’s something that Brannon Braga and I discussed, that Jeri Taylor and I discussed, and we never really got around to coming up with a way of just adding a gay character. So we tried to deal with it in a more abstract science-fiction way.
There are a couple of points that really don't convince me.
1) blaming Roddenberry: virtually every source I found says he was very ready to introduce gay characters but it was the others who vetoed it. Then practically from the third year he no longer had decision-making power. If they really wanted to introduce queer characters he certainly couldn't have stopped them.
2) failing to find a convincing way to introduce LBGTQI+ characters and therefore being forced to use metaphors: gay people simply exist. And they're not mystical creatures that you need a three-episode saga to introduce them and explain their origin. It's like saying "we can't find a sensible way to introduce a red-haired character so we're forced to only show blondes and brunettes."
It's interesting (and here I tend to believe him) that he says that it wasn't the studios' interference and he doesn't even make it a financial issue but simply a creative one. It would have been much easier for him to blame these factors but he still places the responsibility for this choice solely on him (even if perhaps his reasons are not convincing).
By the way, I'm still waiting for someone here to explain how money would be lost by making an overtly "gay" episode.