That’s because Star Wars is wizards in space with WW2 -era warfare. It’s not even meant to be advanced. Besides it all happens “a long time ago”, not in the future. 
But seriously it has about as much to do with the future as D&D rules have to do with realistic medieval combat. Everything is about the rule of cool. It’s not just the tech and rules of physics either, biology gets totally ignored as well.
I watched an episode of Star Trek where they had a prisoner in the brig and it was meal time. So they had one security officer point a phaser at the prisoner while a second security officer shut off the force field door and a third security officer went into the cell and put the meal down on the table. Then the security officer stepped out of the cell and turned the force field back on. They presumably went through this three times a day.
That’s not how real jail cells work. You generally have a small hatch cut in the cell door so you can pass items like meals in and out without having to open the door. Or you have a double door. You open the outer door and put the meal inside. You step back out and close the outer door. You then open the inner door so the prisoner can come out and pick up his meal. And in the Star Trek universe, I suppose you could beam the meals in and out of the cell with transporters.
But the point is you don’t need a complicated and risky procedure that involves three guards and a weapon.
Of course, the truly stupid part is, that’s a force-field door to the cell.
When there’s a power outage in the modern-tech real world, the prisoner is still locked behind solid bars. When there’s an interruption in the Trekverse…
Computers can’t use The Force.
Yep, and in fact WWII combat wasn’t all that cool either. Operation Barbarossa used hundreds of thousands of horses to pull men, supplies, and artillery into Russia on wagons. All just 30 years before I was born. 
Of course if all power fails, you no longer need a cell door, because everyone including the prisoner dies due to 0 life support and other things
There’s a heck of a lot of this in sci-fi, where it seems the writers are too ignorant of how mundane things work in the real world and end up inventing a high-tech fix that is profoundly stupid.
Not quite an example of my OP by inspired by the posts here: the idea that you could have AI androids like the one in Alien or Data from Star Trek or for that matter the droids in Star Wars and not have those worlds be totally different than what is portrayed therein is, when you think about it, quite laughable.
Shapeshifting aliens? While the double door may work it takes up space, and we all know how tight these Starships are as we hardly ever see a toilet. But the door to put food through is just asking for some alien to leach out.
And one example of this is going from the battle droids in the Star Wars prequels to the clone troopers/stormtroopers in the OT. Sure, the battle droids are total retards that could easily be defeated by just about any army with guns in human history–that’s a flaw in itself. But going from strong AI plus guns (that miss, per TriPolar above, but shouldn’t) to meat soldiers that can’t aim at all is just… dumb as hell.
Well, they fixed that in the reboot. When McCoy wants a sample of Khan’s blood, he creates a small hole in the brig’s force field, and has Khan stick his arm through.
Well, yes, if all power fails, it gets real grim real fast. But I’m not just spitballing, here; I’ve seen that exact scenario – forcefield power going down, even when the rest of the ship is still functioning pretty well – play out, such that the prisoner can step out of his futuristic cell like a guy who isn’t on the brink of death, as he lives at a time when forcefields have replaced prison bars instead of adding to them.
(The other three walls? Solid. That fourth one? Doop de doop de doo.)
This. So much this. Decisions were made that reflected the original vision/aesthetic George Lucas chose when making Star Wars: the old-timey Saturday Matinee “Buck Rodgers/Flash Gordon” serials.
Considering the tech-levels existing even in 1976 for aerial warfare, Lucas could’ve easily adopted radar and missile heavy starship combat, that, while more “realistic,” may have looked boring on the big screen. So he went with WWII-era footage to model his starship combat.
The OP (and others) posit legitimate tech-loopholes that generate plot-stupidity; but I think it’s also important to consider the “original vision” of any given material’s creator, as well as the execution of the vision (drama, and such) in determining what’s stupid and what’s not.
Let’s face it; if the X- and Y-wings simply acquired “missile lock” on the Death Star and fired off dozens, hundreds of autonomous missiles, using radar-mapping/terrain-matching seeker warheads, while the Death Star looked (visually) no larger than the tip of their finger…well, then, it would’ve made for a much more boring space battle, no matter how “realistic.”
I think David Weber’s “Honorverse” has most of the ingredients for a big-screen treatment, with the sole exception of it’s space-combat system; ships waaaaay beyond visual range (think ship’s in Earth orbit shooting at ship’s out around Jupiter) shooting scads of missiles (by later novels, they’re literally shooting millions of missiles) at each other!
I’ do enjoy seeing through a lot of this kind of stuff too, but there are SOME things that aren’t QUITE as stupid as they seem.
I’m recalling how in World War Two, it was discovered that even the best tanks had to be accompanied by infantry out in the open, due to the tanks having huge blind spots, and that enemy infantry could sneak up on them and disable their treads and destroy them with small explosives.
Also, the problem with armed forces based entirely on air weapons, means that any situation which doesn’t consist of zooming in, killing a couple of targets and then leaving the area, will be invulnerable.
But yes, among the many horribly idiotic things in the Star Wars episode three film, was the space battle which had ships which fired friggin BROADSIDES at the enemy, circa 1750, including openings into space that they fired through, people in space suits loading them manually, and an inability to direct them in any direction but ninety degrees off the side of the attacking vessel. They even ejected giant “shells” that had to be dealt with manually.
I don’t know if it’s canon or fanon, but one explanation I’ve heard is that vehicles require solid ground contact to move through the theater shields protecting fortified targets like the Rebel base.
As for it being so tall and imposing (and thus unstable); it’s a Wunderwaffe. It’s built tall and scary looking because looking impressive is the point - the Emperor and his cronies like their cool looking toys. Like the Death Star, being* impressive* was more important than being efficient or effective.
Star Wars “astromech droids” like R2 and others.
First of all, why would you make an AI that you plug into a warplane and then not have it fly it. Especially in a universe where they had self-piloting droid combat aircraft at least 20 years before.
Secondly, why make an AI that you can unplug from the aircraft at all? So it can be the comedy relief on wacky adventures?
What, you actually thought Anakin could fly a Starfighter at eight years old and Luke somehow qualified on the X-Wing between the time the Falcon landed on Yavin 4 and the Death Star followed them?
As it was described in another setting:
[QUOTE=Jack O’Neill, Stargate SG-1]
This (holds up Go’uld staff) is a weapon of terror. It’s made to intimidate the enemy. This (holds up P90 SMG) is a weapon of war. It’s made to kill your enemy.
[/QUOTE]
Not actually proven! Maybe they can!
(And Han Solo can’t use The Force… And the stupid weapons weren’t designed for Force users… And…)
(I know, I know: “Don’t get cocky.”)
The AT-AT was pretty effective, though. I recall they bounced everything the rebels could throw at them, except of course for the plucky hero’s cunning plan of using the Lasso of Truth on one. I suppose if your war machine is so heavily armored it can laugh at anything on the field, being practical is less important.
Nope, it’s impossible.
Computers don’t have midichlorians.
…quickly runs away