No, you don't need every Doctor to show up in an Anniversary Special

(And other assorted defenses/critiques of Steven Moffat)

The most persistent criticism I've seen of The Day of the Doctor is that, aside from David Tennant and a Tom Baker cameo (and a Hartnell soundalike recording one new line of dialogue to play over stock footage), the other Doctors were present for about ten seconds in the form of stand-ins or stock footage.

Fiddlesticks.

It's as though these people want Steven Moffat, a man famously unable to develop a sufficient percentage of the billions of ideas he crams into his episodes, to stuff more stuff in.

Start with the fact that it literally can't be done. William Hartnell, Patrick Troughton and Jon Pertwee are dead. Tom Baker is physically incapable of running up and down corridors at the age of eighty (and Colin Baker and Sylvester McCoy aren't all that far behind). Did you really want a Five Doctors type story where a significant fraction of the roles were re-cast? Or a Three Doctors type story where one of the Doctors just sits there and dispenses advice to his later incarnations?

I don't. And that conveniently leads me to my second point: it's been done before. Doctor Who is nothing if it's not a show that completely regenerates itself every five years or so. It is completely implausible to bring every living Doctor back, so it shouldn't be done.

And people who whine about 5-9 not being in the special miss the point of Tom Baker's cameo. He's not playing Four in that scene. Moffat is saying that the door is wide open for another former Doctor to show up again as a Future Doctor. (Let's be honest, does Colin really want to get back into that coat?)

So. The Day of the Doctor needed to be a 50th Anniversary special. It was. And on top of that, Moffat actually got to tell a better story than we had in either Three or Five. This would not have been possible with eight Doctors crowding up the plot.

Next criticism: "Steven Moffat doesn't have the guts to actually kill anyone."
This is true, and yet it misses the mark. Killing someone isn't the only way to make a character suffer, but in order for us to care that a character is suffering, we have to care about that character. I'm stating the obvious here, but it's true. Moffat gets obsessed with an idea, be it nanogenes that turn you into a gas-mask zombie, or a building where time moves at two different speeds, or cyborg trees to recycle air on spaceships, or what the name "Doctor" means. And he ignores everything else. Like, say, character. Amy is The Girl Who Waited and Rory is The Guy In Love With The Girl Who Waited, and that's... that's as deep as those characters go. What's weird is that when he sits down to write a proper tearjerker, he can do it; A Christmas Carol makes us cry for Abigail, a character who is introduced in that episode and killed off less than 24 hours after it ends. It's just that zany other ideas get in his way eighty-nine percent of the time.

The two most blatant examples I can think of are the two episodes under his tenure that should have been character studies but degenerated into the usual sort of corridor-running that Doctor Who always does: "The Girl Who Waited" and "The Power of Three." "The Girl Who Waited" could have been an exploration of who Amy was and how Amy and Rory's relationship worked or didn't. Instead what we got was Karen Gillan under some age makeup playing Joan of Nerf and the Doctor being a devious little git. "The Power of Three" could have been what "The Lodger" should have been - the Doctor "going domestic" with established characters with whom he already had a relationship. Instead, the script tries to do about two dozen things at once and ends up being utterly incoherent. Moffat can't do tragedy because he can rarely do character, not because he can't commit to killing anyone.

By the way, Saint Rusty couldn't commit to killing anyone either. Bad guys, collaborators and some redshirts bought it, yes. But actual characters? Rose Tyler lived after promising us she'd die. Every one of the "Children of Time" lived in "Journey's End" after Dalek Kaan promised us one would die (even the Doctor himself had a cop-out regeneration, and no, Harriet Jones doesn't count because nobody remembers her starting immediately after she's exterminated). The Doctor's Daughter was shot and got a proper mourning scene, and even she couldn't stay dead. Concrete-slab-face-girl from "Love & Monsters" probably wishes she was dead. I can think of exactly two Davies-era stories where two-dimensional characters were permanently killed off: "The Impossible Planet/The Satan Pit" and "The Waters of Mars." ("Father's Day" doesn't count because of Alt!Pete.) Neither of these were normal-length episodes; mayhaps you just can't do character development in 45 minutes, and Moffat understands that. He doesn't want to bog his already overstuffed stories down with sacrificial lambs? Fine! There is no problem whatsoever with that.

Next criticism, somewhat related to the previous: "Moffat undid Davies by undoing the destruction of Gallifrey."
And in The Three Doctors, Letts undid Sherwin by lifting the Doctor's exile to Earth and restoring the TARDIS's functionality.  Anniversary Specials are a proven ripe time for rewriting the lore.

Look, I'd be first in line for a pitchfork if Moffat - or anyone else - ever reveals the Doctor's real name. But I don't think that's actually going to happen. I'd be second in line for a pitchfork if Moffat ever decided to re-activate the TARDIS chameleon circuit (I'd be behind the merchandisers). But beyond that, pretty much everything in The Lore is mutable.

Let me give you just one example. Do you think that old-school Doctor Who fans whined that Genesis of the Daleks re-wrote literally all of Dalek history up to that point? Of course not: they whined about the Doctor's infantile morality ("they" meaning me) and the fact that Davros kept coming back afterwards. Is it supposed to be different because Terry Nation wrote both The Daleks and Genesis of the Daleks? Because Nation was a bit of a hack, honest, who couldn't remember whether the Daleks were cyborgs or robots by the time he wrote Destiny of the Daleks. Is it supposed to be different because nobody had seen The Daleks in a decade? Because I'm pretty sure the novelization had come out by then (and those things were treated as canon in the pre-rerun days).

And, please note, that unlike Moffat writing the Cyber King out of existence, he kept the destruction of Gallifrey in the Doctor's memories. All that angst that Nine and Ten had about it, that's still there, because as far as they know, they did destroy Gallifrey. 

Finally, Gallifrey had to be saved. This is no different than the Doctor's exile to Earth at the beginning of the Seventies (or possibly the Eighties; check the dating protocol). Did you really think that Time Lord stuff from the classic series was never going to come back again? Or that the Doctor wasn't going to one day get over it with regards to the Time War and find something new to mope about?

"Steven Moffat is a homophobe."
I would be willing to bet you that the Eleventh Doctor has kissed Rory more times than he's kissed Amy. Also, Moffat created the first recurring homosexual couple ever in the series (unless you count Nyssa and Tegan) in the form of Vastra and Jenny. Being the show's first straight producer since 1979 does not automatically make you a homophobe. So sorry.