There are some science fictions design sins that I just can't stand. I'm not sure why they continue to persist despite the fact that they make no sense. There's some obvious big ones like sound in space but also some less talked about.
Naked Aliens: You see this all the time, aliens that don't wear clothes but have advanced technology and travel through space. I don't get it. I understand it comes from the old UFO reports where people reported tiny, naked, grey aliens. Somehow this found it's way into science fiction writing and continues to this day.
We don't wear clothes just to preserve our modesty. We have to protect ourselves from the cold, the heat and keep ourselves dry if it's raining. We wear specialized outfits to shield us from radiation and airborne pathogens. Work clothes protect us from hazards like sparks, flying debris and chemicals. Why would an alien race remove these protections from their standard set of equipment? Are aliens devoid of emotion and have no sense of personal identity? It makes no sense. You also run into the problem that many of these shows have attacking, space alien armies that don't wear uniforms. Uniforms aren't entirely about conformity but also play a vital role in organization and identification.
Anyway. It bugs me.
Silly Guns: Almost every major science fiction series has a problem designing guns that don't make any sense. I can see guns that are set up for races with different physical construction but you see many five fingered races using stupid weapons. We've spent a few hundred years with some of our most brilliant people designing guns and they all look pretty much the same for a good reason.
The basic shape and features of guns are born of function. You don't mess with the basics when designing a good weapon and get fancy. Even the most extravagantly designed weapons are still basically the same basic shape. Then there's the problem with making weapons that are just devoid of basic things like the ability to aim. Star Trek is terrible at this. Firing from the hip is neat on film but it's just silly. Why would any organization distribute weapons to their members that you can't aim? I'm not even talking about scopes but simple iron sights are almost always ignored.
There's more...but I'll expand in another post...