Lester del Rey in Galaxy Magazine, 1968 (reprinted in Best SF: 1968 edited by Harry Harrison and Brian W. Aldiss):
[2001: A Space Odyssey] isn't a normal science-fiction movie at all, you see. It's the first of the New Wave-Thing movies, with the usual empty symbolism. The New Thing advocates were exulting all over it as a mind-blowing experience. It takes very little to blow some minds. But for the rest of us, it's a disaster.
It will probably be a box-office disaster, too, and thus set major science-fiction movie making back another ten years.
Peter Krämer, 2001: A Space Odyssey (BFI Film Classics, 2010):
2001's most far-reaching contribution to American -- and also to world -- culture arguably lies in the fact that it both inspired the making, and prepared the ground for the success, of two movies that in 1977 marked an important turning point in Hollywood's operations: George Lucas's Star Wars and Steven Spielberg's Close Encounters of the Third Kind. ...[B]efore the mid-1960s, no science-fiction movie, with the exception of a few Disney comedies and adventures about advanced technologies, had been ranked towards the top of the annual box-office charts in the United States, yet, with the help of several re-releases, 2001 eventually became the second-biggest hit of all films originally released in 1968. ...
This double success [of 2001 and Planet of the Apes] encouraged Hollywood to invest heavily in science-fiction...
John Scalzi, "Seven Studios That Reaped Infinite Rewards from Sci-Fi":
All told, out of 70 available top-ten slots for the major studios, science fiction fills 27 -- nearly one out of every four.