There is a difference between hard sci-fi and science fantasy (often also called sci-fi). Something written by Asimov or Heinlein or one of those other authors from the 50s or 60s is more likely to be interested in exploring an idea, realistic or not, than telling a story. A nice recent example is the Mars trilogy by Kim Stanley Robinson - probably not *everything* in it is feasible, and there's definitely some alteration for artistic license or drama, but most of the focus of the book is "what would it actually be like to colonize Mars?" rather than trying to build a satisfying narrative.
Whereas in Star Wars, every science-y idea or gadget/gizmo is entirely to serve the plot, rather than the other way around, so I would call it science fantasy. Obviously there isn't really a strict defining line here, but just because a border is hazy, doesn't mean the two sides don't exist or aren't worth talking about. It might be hazy when a zygote becomes a baby (somewhere in the second trimester?) but they're certainly different.