Maybe they're talking about science fiction based on real science (physics, biology, chemistry, astronomy, etc). I know I'm going to sound like a pedant, but Prometheus it is indeed a movie based on fringe science:
Pseudoarchaeology. But the Prometheus problem is not that. It's just bad writing since there are stories that deal with similar teams but in a better way; like Lovecraftian fiction.
I never expected hard science fiction anyway, since this kind of story has its feet on the ground and rarely go too far from real science (which is boring sometimes).