Star Wars Is Called a "Space Opera." Why?

True. The execs were not very optimistic either. But unlike some movies, where the ending is closed and sequels feel very taped on, TESB was a natural continuation of Star Wars.
Contrast to Episode VII, which seemed pretty tacked on to me. No real growth from RotJ, just a retreat back to where they were before Episode IV.

All stories set in the past are written from the perspective of the present, even Shakespeare. I agree that SW is not at all about the future. Nor does it claim to be, since the first words are “A long time ago…” More a fairy tale than anything.

2001, on the other hand, might have had the 1950s view of the future (though the book did not have the impractical space station, only the movie) but it was still the future. And it still is. I rode PanAm to Africa in 1961, first class, and the experience was nothing like that in the movie. Sure PanAm and the Bell System no longer exist, but that is trivial. Sure there are no laptops or cellphones. (They do seem to have a tablet, though.) Sure there is no Soviet Union any more (though swap in China and it might still make sense.) The important things about 2001 are the interaction of man and technology and the impact of meeting true aliens, and those are just as futuristic now as then.
If I watch an episode of ST:TOS it is very clear they are working from a pre-digital age, with computers but mainframes. I don’t get that antique feeling nearly so much when watching 2001.

I’ve seen those sorts of shows before, but it never occurred to me to link that to the opening of Star Wars, I somehow always figured it was meant to make it grander than that.

When I was in High School, I stayed up unusually late one night and happened upon an old Flash Gordon serial on one of the UHF stations- It was a bit of a revelation, seeing how it started with an opening text and suddenly realizing that this was the direct progenitor of Star Wars. The whole structure of the thing was eerily familiar.