[Mild spoilers for various episodes of Doctor Who up to and including The snowmen.]
1: monsters that are mostly dangerous because of the way people perceive or think about them
You know, like you can’t tell when they’re there because they look like shadows (the Vashta Nerada) or they can’t move if you’re looking at them (the Weeping Angels) or you can’t remember them if you aren’t looking at them (the Silence) or they look exactly like other people (the Gangers) or they appear if you think about them (the telepathic snowmen things).
Nothing wrong with this kind of idea, it’s just getting to the point where this is now the standard type of monster (in contrast to the kind that just shoots you or eats you or whatever) and it’s becoming boring. It seems like even Steven Moffat’s getting bored with them: the snowmen were definitely the most perfunctory yet. OMG they appear when you think about them! Oh it’s okay, just imagine them melting, job done. Wooo.
Makes you wonder whether the next one will be the Ravenous Bugblatter Beast of Traal.
2: establishing a major element of long-term plot and then completely undoing it within the course of the same episode
Amy’s had a baby, wow, this changes everything, they’re going to be parents and— (Oh hang on, the baby’s been abducted and turns out to be a character we already knew about, so Amy and Rory can go back to their previous childless state.) But now the Ponds have had a life-long friend who hasn’t appeared or been referred to ever before! (Oh look, it’s River and now we know who she is and she’s vanished again.) Since the last episode the Ponds’ marriage has become so strained that they’re suddenly on the verge of splitting up oh no how will we cope? (Oh no, it’s okay, they’ve made up and everything’s back to normal.) The Doctor has become lonely and withdrawn to such an extent that everyone in the universe now knows that he never helps anyone ever. (Oh wait, he’s mildly intrigued by something and now he’s just like he was all those years ago in the, er, previous episode.)
Unlike number 1, this isn’t ‘too much of a good thing’, it’s just ‘a bad thing’. But, like number 1, it is very much a Moffat thing. Davies’ big plot developments weren’t always the most original (or the most subtle) but at least they happened on screen and he gave the audience time to actually experience them. In fact it’s easy to do a direct comparison because both the tenth and the eleventh Doctors have gone through angsty phases of ‘I always mistreat and abandon and endanger my companions, I swear I will never have another companion ever again’. Ten’s lasted for five episodes aired over the course of more than a year. Eleven’s (in The snowmen) lasted, what, half an hour? And yes, it was established that Eleven’s ‘no companions’ phase lasted for an extremely long time in-universe, whereas we have no clear idea how long Ten’s lasted; but that just proves the point. Providing the audience with information from which they can deduce how they’re supposed to feel is neither necessary nor sufficient. Before you can take us on an emotional journey from A to B, you have to actually put some work into making us believe we’re at A, especially if we were already at B in the previous episode.
3: companions of cosmic significance
This sort of is and sort of isn’t a Moffat thing. Davies seems to have been working up to it, in a way, but never went as far as Moffat. Rose was of immense importance to the Doctor but not really to the fabric of space and time. Martha had a more pivotal solo role in saving the universe but it wasn’t because she was unusual in a cosmic sense, just because she was an extremely capable and determined human being. Donna got even closer to it by becoming a sort of quasi-Time-Lord, but even that could presumably have happened to someone else in the same situation.
With Amy, though, and apparently now with Clara too, the companions are not just people the Doctor happens to take up with and who prove in the course of their adventures to be remarkable people; rather, they seem from the outset to be focal points for chrono-temporal weirdnesses of paramount importance. Which… didn’t really work out too well with Amy. It meant that her ultimate importance was passive rather than active. She may have done awesome stuff at various points along the way, but her overriding significance in the history of the universe was all about things that were done to or around or through her. Which was a pity, really.
As for Clara, it’s too early to say. Maybe she’ll turn out to be the driving force behind the whole season, a cosmic arch-manipulator rather than the unwitting focus of forces beyond her comprehension. It could be interesting. But I still wouldn’t mind having a companion who’s just, you know, a person who happens to travel with the Doctor?
Spot on. Among numerous other things. Just feels like Moffat doesn’t care about long-term story arcs (or the characters, or good drama, or THE MORALE OF THE COUNTRY THE BASTARD) and just wants to tug at our heartstrings briefly during one episode, I mean Rory died like a billion times with diminishing returns in the tears department, gotta say.