This isn’t true.
Star Trek was a very optimistic view of the future in very turbulent times when it first appeared in the 60’s. 2001 was also very hopeful in its tone.
A few years later we got the dystopian Clockwork Orange, while not necessarily true science fiction it was based on future society.
The 80’s ran the gambit from Blade Runner and Alien on the dystopian side, the best of the best of the Star Trek movies II and IV were the worst of times and best of times respectively. You also had very hopeful Sci-Fi set in contemporary times like ET, The Last Starfighter, Starman.
The genre lends itself to the best and worst in the best and worst of times.
It was in the sense that aliens implanted our intelligence, and then saved us before we destroyed ourselves. But then again, the movie was so abstract and purposely mysterious that I doubt most people saw it that way. I know I didn't. (A person would have to read the book to make any sense of it.)
Quite a few people figure that Kubrick held a very low opinion of his own species.