^By that point, the tone of the show had been set and Berman, who saw his role as basically "keeping it Gene" as he perceived that idea to be wasn't about to depart from it.
Berman was not a creative's producer. He was a studio's producer. Keep the budget under control, don't take too many risks and deliver a "consistent" product was his mandate and worldview.
But Berman clearly didn't have a problem with continuing characters having a relationship, as the other shows have plenty of them, and even in TNG they tried to set up Troi and Worf! Plus Data and Tasha on Gene's watch. Eventually Riker and Troi got together, twenty years later, but I do think it's strange it didn't happen on the show.