A search on "Is sci-fi still a derogatory term?" will find a few
opinions. Here's a quote from one such web page.
<quote>
A lot of hard-core science fiction fans (and professionals) hate, and I
mean really hate, the term "sci-fi." I once heard Harlan Ellison compare
the term to calling a woman "a broad" and calling a Jew "a kike." (Of
course, Ellison's never one for hyperbole. :-) )
</quote>
The abbreviation SF has been around for a long time, and nobody objects
to it. The term sci-fi arrived later, and it tended to mark the user as
an outsider to the field. It most noticeably came into play when
producers started making "sci-fi" film and television productions. For
whatever reason, they ignored current science fiction and focused
instead on 50-year-old space opera and similar themes. And it violated
Sturgeon's Law, because 99.95% of it was crap.
So, for a little while, SF meant what was printed in books and sci-fi
meant what was on the screen, and the difference in quality between them
was glaring. So, to the people in the field, the term "sci-fi" came to
mean "clumsy poor-quality imitations of science fiction". By the way,
some of them pronounce it "skiffy" as a further mark of derision.
Now, of course, the world has aged since then, and new people have come
on the scene, and the younger people probably sincerely believe that
Star Wars is representative of science fiction. The old fogeys, on the
other hand, remain stubborn in their perception that "sci-fi" means the
dung heap of the field.