Why is Russia always the Big Bad?
Really, the first question you have to ask isn't "why is it the Russians again", but "why is it the Americans again?", because if you're making a modern day or near future military action piece (and these are the games which are most likely to feature the Big Bad Russians as villains), it's a sound guarantee that the Americans are going to be around the place.
And the simple reason for that isn't that Americans like the big ooh-rah shooting games and buy more of them (though that is a compelling argument in itself), the reason is that America is the biggest kid in school right now, and a story where the big guy gets a beating is going to have more shock and awe value, and feel like a bigger deal, than one where a 90lb weakling country like Guatemala gets invaded and conquered. It's the same principle as when the might of the Royal Navy (at the time by far the strongest fighting force on Earth) was shown to be worthless against the Martians in the original War of the Worlds. The audience understands that they just saw the biggest army they know take a kicking, so they know that shit is now officially real. So now we know why America, does that answer why Russia?
Well, yes, frankly. Russia is currently the only other kid in school who stands a credible chance of threatening America proper. Given 20 years China might step up there (and we're kinda seeing the start of that in Homefront, though that's got a bit of extra wackiness given that the plot appears to be "North Korea conquers world with mad Starcraft skillz") but right now they don't have the force projection capability, and even united nor does Europe as most of the EU militaries are for national defence. If you're going to have a Big Modern War, Russia and America are the only combatants you can fight it with, and even people who don't read anything about military forces know that this is basically the case. And that fact is so pervasive that even if you make up some pretend countries you're by and large going to end up with Russia and America with the serial numbers filed off and a new coat of paint.
Why the faceless protagonist
This is something much deeper, something that really goes to the core of what game narrative is and how it's different from any other form of narrative. The core of it is expressed in what Danny Bilson said here [http://www.escapistmagazine.com/forums/read/7.269677-Cutscenes-Are-Gamings-Failure-State-Says-THQ-Exec]. When you pick up a controller not a TV remote or book, it's because you wanted to interact with something. The old maxim of "show, don't tell" starts giving way in games to "do, don't show". But this presents a new challenge to a storyteller, and it's a challenge that comes in two parts, The first is probably best expressed by what Dara O'Briain is saying here:
Games are presenting another challenge beyond simply allowing the story to progress, the audience now has to earn the ability to progress, they are actually facing the challenges the protagonist faces. The second is that the audience has, to varying degrees, a power of agency. The less prescriptive the game is the more agency the player has to alter the way the story is experienced (even a very linear narrative can be nonprescriptive, if there are even as much as multiple gameplay solutions to the same problem then two players can create different "characters" for their protagonist via their limited choices of how to use the tools on offer. If two people play Deus Ex then their versions of Denton could be very different characters even if they make all the same choices at branchpoints because they interacted differently with the tools of the game).
What these two points mean, taken together, is that the motivation to proceed must be transferred from the protagonist onto the player. Going back to Dara O'Briain and the Berzerker in Gears of War, the game didn't really have a lot of narrative in the first chapter, consequently it hadn't made Dara care about proceeding enough that he actually wanted to beat the Berzerker. If it had, then he would be in the position we've all been in having faced a difficult boss, we got through it by dogged perseverance and eventual improvement at the game because we wanted to win.
This key difference in where the narrative motivation lies is the source of the difference between an effective videogame protagonist, and an effective protagonist of another medium. Because the player is an active participant in the story, taking on the role of the protagonist in driving the narrative even if they don't take on the personality of the character in that narrative, the author of the story needs to convince them to share the motivation of that character. And the best way to do that is to keep that motivation very simple. In Red Dead Redemption, for instance (a recent game to be lauded for it's story), John Marston's initial motivation is incredibly slight, get his family back. That's an easy buy-in for the audience (though it would have been enhanced by having some of the family ranch stuff at the start of the game, so the player "knew" the family), but any subsequent motivations that drive the narrative (the desire to save Bonnie, for instance), are impressed on the player more strongly than the character. The player wants to proceed with the story in large part, despite there being a good deal of extraneous fucking about available to do. If you create a character with complex or conflicting motivations, it's harder to convince an audience to share in those motivations, and whilst it might be interesting to see what happens to a character like that (see: Hamlet), it's not enough to motivate an audience to overcome gameplay challenges, because they have to want to do more than know what happens next.
And so we come at last to the Tabula Rasa. Since we've already established that we're having to spend more of our effort as a storyteller impressing the desired motivations onto the audience rather than crafting intricate motivations for the character, why not cut out the middleman? Don't even give the player character the one line brief that comprises most videogame character motivations, just make the player themself want to do something. Save all that character development time for the characters that need it, the NPCs and especially the villain, because if you make a really great villain you've got an instant player buy in in the desire to defeat that villain. In terms of the character impact of a videogame, one Irenicus is worth a hundred complex and nuanced protagonists.
A visit from the exposition fairy.
The reason the exposition fairy has become so common recently is again down to the desire to remain interactive. A voice in your head like Cortana can witter on without breaking the flow of gameplay, you don't have to break into a cutscene to let the exposition fairy do her work, so you don't have to take control away from the player. Even when you're doing the Gears of War thing and making the player walk around slowly with their finger in their ear because you're secretly streaming the next area off the disc and want them to slow down so you've got time to do it.
Also, when you've got the whoosh bang explosions going on for the rest of the game, having mission control be calm and controlled makes a very useful break in pace. It's relatively easy to do that with a female voice and still retain some level of verisimilitude because it's easy to have that kind of character in your story, but there aren't many male characters you can put in that role, the only one you can really use is the Roy Campbell type, an experienced warhorse who isn't quite so excitable any more and so remains calm no matter how much pressure is on the player at the time. (though MGS has the break in gameplay for the codecs, initially due to the limitations on streaming from disc on the Playstation, even if it didn't Col. Campbell would have fulfilled that as mission control, and it would probably be more affecting when he goes batshit at the end of MGS2).