TL;DR: Skyrim is uncanny.

Exhibit A:  nightmare fuel.

I've played a lot of Skyrim and emerged feeling unsatisfied.  Being a thoughtful sort, I started to ponder why that's the case.  Even if the interface, incongruities, scripting glitches, bugs, etc., were all tip-top, the game would remain unsatisfying for me.  What is it way deep down in Skyrim that's wrong?   And I've concluded Skyrim's basic problem is that it's uncanny.  As in “uncanny valley.”  When a human replica looks or moves almost—but not quite—like an actual human it provokes strong negative emotions in human observers.  Think of corpses and zombies.  The idea is that the high fidelity of the imitation makes its unnaturalness grotesquely obvious.

I’m only using the concept loosely here because Skyrim’s simulation of a world inhabited by agents and artifacts ruled by psychology and physics doesn’t even loosely resemble the real and what it inspires in me is not revulsion but an eerie feeling of emptiness.  Skyrim’s design underlines the game's limitations in a way that forever sabotages its illusions and reduces my investment in its world.

Skyrim is often self-defeating.

When Bethesda crank out another link of Elder Scrolls sausage, they aim to create a solipsistic open world in which the player is the protagonist of an epic saga that's sufficiently relaxed to allow significant wandering from the plot.  Sort of a boilerplate RPG with open-world elements.  Which is cool, but the openness of an open-world game comes at the cost of depth.  Our technologies of simulation are not sophisticated enough to maintain a consistent illusion of player impact in a complex world. (For a more rigorous treatment of this point cf. chapter one of Consciousness Explained, in which Dennett examines why hallucinations are weak.)  The necessary lack of depth is okay in an action game but problematic when more meaningful interaction with the world and its characters is desired, e.g. in an RPG.

Consider that familiar Elder Scrolls anticlimax, becoming a guildmaster.  In Skyrim, my character heads the College of Winterhold, Thieves’ Guild, Dark Brotherhood and Companions.  “Jiminy Crackers, how does he find the time!?” you ask.  Well really it’s not that hard.  Guildmastership in Skyrim is like romance in Dragon Age:  no strings attached.  Scurrying up each guild’s respective ladder taught me that a guildmaster’s primary responsibility is to hang around getting old until a neophyte gravid with destiny joins, then provoke a crisis and die so the new guy can resolve it and take over.  This is something I can easily do for 40 hours a week.

But I’m wandering a bit here.  Let me get back on track:  the emptiness of guildmastery draws my attention to the fact that the game is simulating only physics and the rest is a rigid body of script.  Each guild's quest line positions me as the only member capable of guiding it into the future.  It's my destiny.  But when the script reaches its end I'm left alone on stage listening to the eerie quiet of a deserted theater.  Only after the show do I realize it's been only me up there all along.  The guild is uncannily unchanged by the recent destruction of life and property.  There's no acknowledgement that anything interesting has occurred and no further meaningful interaction with the guild is possible.  Brynjolf still calls me lad and always says he’s too busy to talk to me.  I’m your boss, damn it!  Brelyna still wants me to help her with her homework.  How dare you speak to me!  It's as if instead of renewing the organization I've entombed it.  Thousands of years from now the (unchanged) people of Winterhold can look at the College and see it as it was thousands of years ago, thanks to my tying up all its loose ends.  And I'll be there to say, "Yep, I did that."

I don't think this is due to lack of effort at Bethesda.  The illusion of change surely could be enhanced by greater attention to detail, e.g. more lines of dialog for more characters—have you noticed guards are the only people who stay up to date on your career?—but that’s just rearranging furniture on the Titanic.  The root of Skyrim’s emptiness is at the core of its design; its original sin is the decision to open the world.  In attempting to create a sandbox in which the player can do anything, Bethesda have produced a world in which it seems one can do nothing that matters.

No game can generate an infinity of new, varied content; this is why games typically have distinct ends.  I've enjoyed Skyrim, void at the core of its being and all, but I'm more satisfied when a game narrows my range of action and focuses my experience.  It's okay when I change the world and exit the scene forever, before the curtain's drawn back and I see the Wizard's poverty.  I'm thinking of Baldur's Gate II here--once an area's cleared there's nothing left to do, so one moves to the excitements of the next until at last the grand conclusion bookends the game.  There's nothing left to do but it doesn't matter because the game's over anyway.  In Skyrim, once the world's cleared and all quests have been reduced to completion, it's as if Tamriel has died a heat death:  we see the new world forever the same as the old, ticking away to infinity.