Stormtroopers get killed a lot. They’re not the best shots, and their armor isn’t exactly blaster-proof. In fact, I think they’re basically wearing oversized egg shells. You can take out your average Stormtrooper with a rubber band. What, you think the Empire is going to outfit their cannon fodder with top of the line equipment? No, Stormtroopers are essentially walking casualties.
But that’s not something you find out until you’re knee deep in the original trilogy.
Because when they first showed up? Those guys were scary. In fact, they were almost the scariest thing in the movie, before a large behemoth dressed all in black with a strange way of breathing showed up.
But what made them scary all those years ago, when those of us laid peepers on what was just called Star Wars without the “A New Hope” rider?
It wasn’t what they did, although when actually did something they did it with style and panache. No, the scariest moment in the original trilogy — outside of completely traumatizing senior citizen lightning hands and Rancor attacks — is the reaction of the Rebel Troopers on the Tantive IV just seconds before the Stormtroopers burst in. 
I think the prequels have obscured how good a director George Lucas was when he was young and actually in love with the art of directing a movie. He knew how to build tension and suspense without words, how to build a sense of dread without overplaying his hand. You can see a bit of what I mean with this when Luke first sees that the only family he has ever known was charbroiled. There’s no useless bellowing of the word “NO!” or melodramaticism at all. There’s no need for anything but exactly what we see, and it tells the entire story in less than 30 seconds. We KNOW what happened, we know what Luke is feeling, we know the entire story there, and not a word had to be said.
The same mastery of scene is on display at the beginning of the movie. At this point, coming into the movie cold, we don’t know what’s coming. We know an impossibly huge ship has captured this tiny little freighter for some reason, and we know everyone is extraordinarily unhappy with the situation, but we don’t know why.
Lucas lets the moment build. We see the clenched, restricted anxiety on the faces of those rebel troopers. We hear strange sounds. We see unsteady hands with death grips on blasters. When finally the door breaks open and the Stormtroopers bleed into the scene, gleaming white with liquid fire shooting from their guns, we know exactly what the rebels feared. Stormtroopers fell, but more were there to take it’s place, like trying to dig a grave in a mudslide.
Eventually Darth Vader would make one of the best appearances to grace the silver screen, an ebony god with the voice of doom, striding down pristine corridors littered with the bodies of friend and foe alike. But before he showed up, those Stormtroopers were the face of fear.
This long-winded buildup is leading to a point, and that point is this: I have Stormtroopers. I have plenty of Stormtroopers. But what I don’t have, is any of those Rebel Troopers for the Stormtroopers to shoot at. This has created an imbalance in the little 6-inch world of Star wars toys. How will I ever truly know the dominant superiority of those Stormtroopers I have if I don’t have a similarly impressive passel of rebel troopers to soak up their blaster fire? If I can ever lay my hands on that new 40th anniversary Vader that we’re all being persuaded to buy to replace the lame first attempt, who will I have him lift up and choke, if I don’t have a Rebel Trooper? Where are the plans, man, where are the plans? Oh crap, broke his neck, can’t find the plans that way. Tear the ship apart, but … ignore that pod. Yeah, just ignore it. That’ll work out well. 
We’re pretty deep into the 6-inch Star Wars world, but still no army-building Rebel Troops to die over and over again.
Those swanky helmets must be made.