As a species, we are tool makers first and foremost. That's why we love to see gadgets in our movies, and to watch our Captain Picards and Batmans and David Hasselhoffs defeat the bad guys with technology we know we'll never own.
But in the course of trying to dazzle us with their fancy spaceships and battle vehicles, sometimes Hollywood forgets to make sense.
6The Imperial Walker
The dreaded Imperial Walker, or All Terrain Armored Transport, is frequently considered the single coolest vehicle in the entire Star Wars universe.
The moment the rebels spotted these things on the horizon in The Empire Strikes Back, the only question was exactly how much of their stuff they could pack before they flew screaming off the planet.
"Fuck it! Leave the porn, leave everything! RUN!"
In addition to being huge battle robots of death, the Imperial Walkers also boast a blind spot in excess of 300 degrees. The thing can't turn its head. Specifically, it can only turn its head this much:
This is not a minor issue. That up there is an AT-AT trying to shoot an enemy ship that's flying past it. That's as far as it gets; it's like a huge, muscular guy who happens to have his head frozen in a neck brace due to a crippling spinal injury. The only difference being that guy could still conceivably punch an enemy by swinging at him wildly. Meanwhile, all of the AT-ATs guns are glued to that non-swiveling head.
"Two targets for the price of one. Nice design, Kuat Drive Yards."
This would not be a problem if, say, the walkers were extremely fast and maneuverable. For instance, in the real world, jet fighters have all of their weapons pointing forward, too. But they also go faster than the speed of sound. These bastards, on the other hand, have the top-speed of a Geo Metro driving across a river. It takes them what looks like an entire day to execute a full U-turn. That's good news for you if you're Luke Skywalker, because if you get within 20 yards of one, it can't hit you to save its life.
Years of additional weapons development actually lead to shittier war machines.
Also, the Empire seems to have constructed the Walkers without considering that most militia battles are not fought thirty stories above ground, so the tank commanders spend the entire day on Hoth with their chins to their chests trying to see what the hell they're supposed to be shooting at.
The only reason the rebels had such trouble with them is because the speeders insisted on using what Luke referred to as "Attack Pattern Delta", which appears to mean, "fly directly at the enemy in the one single spot where they are able to shoot us."