I'm thinking that it's not so much realism, but a lack of attention to detail by either script writers or visual effects people,and I feel it's one of the weaker areas of Science Fiction on TV and movies. Whenever something specific is mentioned, 90% of the time, it's completely factually wrong, and it's as if nothing was researched and it comes across as really lazy, and it's an area where things could be educational if done right, but they take the easy way out. I mean, I understand that Science Fiction has some fantastical elements, but to the things that are known factually, there's little to any excuse for any of this to be happening.
To be fair, it's not just Science-Fiction, but anytime science is invoked in a TV show, or even a commercial. There's a recent Little Caesars commercial, as an example, where a father and son are doing some astronomy in a field. That part they got right as it looks very much like what someone would be doing if they were out observing. The setup is good, but: a) keen observers would note that there's bright white light shining in their faces, blinding them and preventing them from seeing anything. If you were to bring white light to an observing site, one would be promptly yelled at for doing so and told to turn off their light. And B), the scope is pointing in the wrong direction, where he'd be seeing his knee instead of the sky. Both things could have been easily researched and fixed, and the result would be a red-light shot which would more astronomically correct and likely also get a better atmospheric shot.