Was going through the MemoryAlpha archive looking for those really awesome TNG episodes, got to the Darmok page, and... there's this:

"I've seen lots of Star Trek: The Next Generation, I think it's a lovely show - but there's one episode, the billing for which is so fascinating I've actively avoided ever seeing it," Davies explained. "I love the idea so much, I'd rather think about it. Forever. The episode is called 'Darmok', and the synopsis simply says that Captain Picard is trapped on a planet with an alien who can only talk in metaphors. Wow. That sounds brilliant. How does that work? What happens? How does it end? I've got no idea - not seen it! But it keeps resonating with me. I've just looked up its TX date, and it's almost 20 years old. I've been thinking about that story and its potential for almost 20 years! Would it have sustained itself for that long in my head if I'd seen it on BBC2, long ago in 1991? I think the mystery keeps the concept alive. Here I am, still wondering, right now! And I can see the idea bleeding into my own work. In 2008, I wrote a Doctor Who episode called 'Midnight'. Is it like 'Darmok'? I don't know. But stripped down to its essentials, it's a story about a hero, an alien, and words. That's practically the same billing. Maybe the two shows are profoundly different, but I know for a fact that all those years of wondering about 'Darmok' led me to that script."

I offer it without comment, simply because I feel it explains oh so much about RTD's writing tics.