It can have all the mechanics it wants in order to encourage movement, but it didn't actually succeed. If you give a player a gun they aren't going to assume it does more damage close up. They're going to try to use the gun as an effective ranged weapon... You know, like a gun.
This is also a massive problem I have with the series - as well as game feel.
There is not a single enemy that encourages you to leave cover. This notion that if you play it as a cover shooter you are playing it wrong is nonsense and infuriating.
If a game rewards you for playing a certain way and does not design it's encounters or enemy types in a way that forces you to move its a non-argument.
I do actually use the verticality of the environment but people who don't - and just as easily make it through the game - are not playing it wrong as some would have you believe.
If Naughty Dog's intention was to force players to move they failed.
Which feeds into my post about Gears of War encounter design, the composition of enemies within any one fight and the way the mechanics and weapons feed into the overall design philosophy. It takes a less is more approach and is all the better for it.
Gears of War 3 takes meaningful steps to force you to move through both enemy and encounter design.
Lambent enemies that can attack you over cover and force you to target specific limbs - don't kill them quick enough and they morph into worms that actively seek you out in cover and can only be attacked from behind.
Then you have enemies that are given diggers - explosive ammo that burrows under ground and seeks you out in cover - which forces you to move or die.
You're even given a new tool, the mantle kick, to encourage you to be more aggressive and move around the battlefield more.
Gears of War 3 is also designed around four-player co-op, so battlefields are big, packed with different angles of attack for people and have lots of power weapons, that specifically make the encounter easier, hidden away in parts of the map for players who are willing to move around.
In previous games, though more specifically the second one, they also do a great job of mixing up encounters with varied enemy types.
You'd have a Kantus, which can spawn in explosive tickers which charge you, supported by drones, grenadiers, boomers and so.
However, a Kantus is usually placed on higher ground, behind the others, and can revive fallen locust. So, you either target the Kantus first, get in close, or pick off enemies until you can find a gap in time to attack.
There's also other enemies like bloodmounts that are two locust rolled into one and can hop over cover. If you kill the mount from a distance the locust riding on the back will get up and continue the fight and vice versa.
Gears of War's biggest strength is its varied arsenal of weapons and monsters. However, cover placement is also very deliberate.
Even the original Gears, which is relatively simple, demonstrates some great level design, particularly in the second act as you make your way down dark streets, blowing up canisters for light, taking out lights above enemies to kill them and in some cases completely skip encounters.
Which is another thing, lots of fights can be completely skipped if you close up e-holes in time.
Best of all - most encounters are with a handful of locust. They are small bite-sized encounters which push you into the next area. Uncharted relies more heavily on the sheer number of the enemies you are fighting (Uncharted 2 less so).
I am not trying to argue Gears of War is an dynamic as Uncharted because it isn't but I think it's a lot better than people give it credit for.
It's good, simple design, enchanced by and built around its enemy types.
There's also some really interesting sections such as within the giant work in Gears of War 2 involving time-based movement and shooting on the move.
There's lots of specific encounters I could mention but I suppose that's the gist of it for me.
By the way, I will stress that I love Uncharted 2 and 3, just not as much as Gears.