Reality isn't a video game. Again, in reality, you move your head a lot when doing things like reloading a weapon. You can't do that in a video game because no one wants to take camera control away from the player. Which means you need to have the whole animation clearly visible, which means doing this weird reload dance at eye level when it would mostly be done at you waist IRL. Which looks weird.
Are you sure reloading is done at waist level? I am no professional soldier but I looked up some reloading videos on youtube and the gun hardly ever reaches near waist level. Or do you mean the magazine is at waist level? Why is this an issue? I am fine with the reload animation being partially cut off if you are looking too high to see it. If you really have to see it all for some reason, then look down.
There is only one right way to reload a weapon, and if you mocap it really well, it should look correct both in third and first person.
Actually, I'm wrong about reloading magazine fed weapons. It's perfectly doable at shoulder level. Reloading, say, a shotgun at shoulder level is a lot harder. Reloading a bullpup weapon while prone is probably best done on your back. Belt fed weapons are a ***** to reload at shoulder level too. It very much depends on the weapon and your stance.
You keep on saying that this is doable because real life does it. That's completely idiotic reasoning. Video games aren't real life. You can't simulate real life when you're looking at it through a screen. Real life never looks jerky because real life doesn't have preset animations. That gameplay preview is just one long example of animations get interrupted by other animations. It's pretty typical for 3rd person FPS models, but CR has seen fit to grace us with that **** in 1st person too. You think it looks fine. I don't. I think that Star Marine demo is one of the worst looking examples of gunplay seen in a modern AAA FPS. When ARMA has smoother animation than you do, something's gone very wrong.
Actually, the ARMA 3 comparison gets interesting. ARMA 3 has gone with making 1st person animations look smooth, and as a result 3rd person animations look stiff. SC, for some reason, has decided to make the 3rd person animations look good (which they might eventually), which results in 1st person animations looking jerky and exaggerated.
3rd person animations in 1st person look overdone. 1st person animations in 3rd person look underdone. This, I think, is a fundamental issue related to perception of space in FPS game. Specifically, FOV. FPS games always have a narrower FOV than you do IRL. There's no way to fix that except to make a VR system that wraps around your head (so not Oculus). This means that animations that looked fine from the mocap model's point of view take up a lot more visual space on screen (exacerbated by the camera itself being zoomed in because of the narrower FOV), which makes the animation look exaggerated. This is also the reason why the pistol ADS looks like the character's arm/shoulder is jammed in the player's face.
This is not something that can be fixed as long as we're using desktop screens. This is probably the biggest reason everyone making FPS games "cheats" on animations. To make up for the narrower FOV, 1st person animations look much better when the movements are underdone. 3rd person models don't have this restriction.
The other reason is that rapid animation transitions, like going from sprint to a complete stop, looks like ****, and the only way to "fix" that would be to delay responses to allow for a transition animation to play. Bad idea for obvious reasons. The understated animations typically used for 1st person models are designed to not jerk as much.
TL;DR: They can't make these animations look good as long as FOV discrepancies between real life and FPS games exist.
EDIT: Battuta and Scotty beat me to it.
Tangentially related: I love how the Glaive sale is "clear the enemy waves in Arena Commander to earn the privilege of giving us 350$ for yet another nonexistent ship. Hurry, only 1000 available".