William Gibson: The Rolling Stone 40th Anniversary Interview : Rolling Stone: "It has to do with the nature of the present. If one had gone to talk to a publisher in 1977 with a scenario for a science-fiction novel that was in effect the scenario for the year 2007, nobody would buy anything like it. It's too complex, with too many huge sci-fi tropes: global warming; the lethal, sexually transmitted immune-system disease; the United States, attacked by crazy terrorists, invading the wrong country. Any one of these would have been more than adequate for a science-fiction novel. But if you suggested doing them all and presenting that as an imaginary future, they'd not only show you the door, they'd probably call security. "
This is just too sweet as I have been reading SFF for about that long.
Some other SFF writer spoke on how hard it was to write good Scifi since it had to sound plausible. Reality is under no such restriction.