alt Hacker NewsSpace opera is still a subset of speculative fiction and science fiction, saying "just" dismisses its influence on the genre as a whole.
A lot of classic science fiction is basically "x with spaceships" where x is the Napoleonic Wars, or feudal Europe or the Wild West or what have you, and the "science" is little more than set dressing.
> saying "just" dismisses its influence on the genre as a whole.
Well, it was meant to be parsed as:
Star Trek is speculative fiction and space opera.
Star Wars is just space opera.
Some space opera is also speculative fiction, but I wouldn't say it is a subset. I wouldn't call some space opera stories speculative fiction at all.
They're all classified as science fiction.
(Yes, yes - there is no consensus on these terms...typically science fiction is considered a subset of speculative fiction, and here I inverted a lot of things).