Rose is a masterstroke. Best intro for any new fan, period.
Which makes his decision to rewrite The Reality War genuinely baffling. Why does it have to end with a regeneration? Why not replicate Survival so that, the next start can be as surprising as Rose was?
Because they’re *his* toys now. He came back to save the show, and it would probably (and is I imagine) cause sadness to him if he actually finishes it off instead. Even the 60th was a celebration of how his version of the show was so great and wonderful, and how bad it’s been since he went away (that’s alright then!) but it’s ok, because now he’s back! (But we’ll just keep Tennant in the back pocket, just in case…)
Billie is there to do much the same thing, but also to leave a very specific finger in a very specific page, or a towel on a sun lounger. Because one day, He shall come back. And we must go forwards in all our beliefs, as — *scratchhhhhh*
Even ignoring the end of Reality War, that finale was more of a sign of not having a handle on things. More so when you consider The Story & The Engine was almost a metaphorical re-telling of the story of Omega and the Time Lords, and we still had whatever the feck was happening in that finale just an episode or two later. He’s writing for a New Audience he can’t quite understand, and has forgotten or ignored the Old Audience (or pushed them away) because he has lost contact with those too. I’m not sure he’s even writing for *himself* even, but perhaps, and that’s not usually a good sign in these things.
He also doesn’t have or doesn’t really use what he had in 2005 — a bunch of writers and concepts that were ready to be part of the show. All he has left is the addicted Moffat, and using him is kind of a break-glass option, and doesn’t play well with the ego he now has.
Perhaps he’s just one of those writers who can start a thing well, but is terrible at through lines and resolution. He’s only really managed it once, and ironically that was *helped* by having his lead go out the door. Maybe one-and-a-half and again helped by the weight of a lead actor parting ways as it were, an accidentally advantageous doomsday.
His plans always lack what might be called trap-door writing though, and so they get derailed usually, and we really notice that on screen.