@Senile Old Pony
 
And the comment award goes to

der fings i duz fer more dakkaz, lookin’ after der runt pony’s da boss sez, ‘ill be a larf e’ sez

@DudeManGuy  
And also because the power armor for regular humans isn’t the same as power armor for Space Marines, which require the black carapace implant.

I’m da prettiest, so I’m da BOSS. BAUS IS BOSS and Baus sayz you Boyz just needz ta make it more CHOPPY.

DIS THING NEEDS MORE DAKKA!!!

I would be the happiest ork right now…

@DudeManGuy  
That and the whole religious thing…and steroids with other genetic stuff…yeah…

@Background Pony  
They can sometimes be trained to wear power armor, but they can’t be Space Marines. Being a Space Marine is a lifelong commitment you start pretty much as you’re just hitting puberty.

@TobiasKazama  
Guardsmen don’t become Space Marines. You get picked as a Space Marine from a young age and spend all of your teenage years undergoing training and enhancing. While a normal guardsman can in fact be trained to use power armor, they’re a lot less adept at using it because for Space Marines their enhancements make it almost literally a second skin for them.
 
Also, Eldar suck.

Boss neva said nuffin’ bout no stinkin’ ’orses…

Da tini horsies makin mi go WAAAAGH!

@TobiasKazama  
For the record, I’m pretty sure Guardsmen can’t become Space Marines.

they told me they would give me moar daka but instead i got moar bland flanks.

NEEDS MOAR DAKKA!

And I want a Warhammer 40k singleplayer FPS: Where, for the first 30 minutes, you play as a guardsman fighting cultist in a huge imperial city.  
Then your planet gets attacked by orcs and you get a 1 hour desperate fight though Muddy trenches.  
You get promoted to a veteran and is flown off world for 2 hours of spaceship boarding action against the orc fleet, fighting side by side with the Ultramarines who’ve arrived to save the day.  
Impressed by your actions, the marines select your to join them. Years later: You are a Space Marine Scout battling the Eldar And Dark Eldar on a jungle world for 3 hours of intense action.  
Years later… You are finally a true Space Marine of the Ultramarines Chapter. And you are fighting the dammed Chaos Marines on a battered forge world! (5-6 hours here).  
The game ends with a 2 hour climatic battle on a corrupted world in the outer systems where you, now a Veteran Sergeant, lead Space Marines and Eldar in a charge on a massive Chaos Army, which is protecting an immensely powerful, 5 year old, psyker who if corrupted could spell doom for the universe. Your mission: Eliminate the child before she destroys us all!

I want a Warhammer 40k video game where you play as an ork. Aside from an RTS, that is.