"I did once go and see [former Doctor Who boss] Russell T Davies and he said he thought I was far too adult for Doctor Who. But he was creating [Doctor Who spin-off] Torchwood and so he said to go away and come up with some ideas. I had very few clues what it was about, so it was like throwing darts at a dartboard in the dark.Most of us had very few clues as to what [Doctor Who spin-off] Torchwood was about even after it was broadcast.
"That was the closest I ever came. Although I love Doctor Who - maybe I'm not the right person to write it."
Anyone can write for Doctor Who, and for RTD, the creator of Queer as Folk, to give his reason for Ravenhill not being able to write for the series as him being "far too adult" is bizarre, unless it was after Mark had already submitted some ideas for the the main show.
Either way, [current Doctor Who boss] Steven Moffat should give him another chance.