I would argue that, in fact, they did do that. They just kept it extremely low-key. Every time you hear Garak tell Bashir “your pants are ready to be picked up,” that was their fuck code. Nobody in the galaxy has their pants altered that often.
That, and there is plenty of fanfic to fill the void. A little cowardly to leave it to the fans, but it's not like they didn't build the foundations. The writers deserve some credit.
There's also that segment with Andrew Robinson in some DS9 docu where he states his opinion on the matter pretty clearly. Can't remember his exact words, but his vibe was one of "shoulda let us have fucked".
He speaks pretty bluntly almost every time he’s interviewed about it, but the one time he speaks the longest about it is in the DS9 documentary what we left behind. He’s great.
It's been bloody hilarious if you're long term fan, he's gone over the years from coyly hinting at vague interests other than espionage to where we're at now, where he's outright saying 'my motivation was i want to fuck this beautiful man'. Mostly due to society getting its head out of its arse, but still, hilarious