At least with Ridley Scott’s sci-fi films, you can track the logic of the choices the characters are making…
It’s not a stretch to say that one day we will have commercial spaceships and meet deadly creatures or that corporations become more powerful than the government; it’s harder to believe that we can get dosed in gamma radiation, turn into giant green rage monsters, and then go fight crime.
You might be quick to point out that some of Ridley Scott’s most popular films, namely Blade Runner and Alien, aren’t very realistic either, but I think the point he is trying to make is that those films at least exist in some realm of believability, either in the world or with the people.