Yes indeed, Mary Anne. In fact, I recall in high school our literature books had ONE SF story, from Ray Bradbury. It was one of the Martian Chronicle stories, about a Johnny Appleseed type who plants trees all over Mars to give it more oxygen. Nice, but hardly exciting or revolutionary compared to what I knew was out there.

I am always amused when a "mainstream" author decides to go SF and the mainstream critics get all excited, like they've never seen this type of thing before. Of course usually the plot and theme have been done dozens of times in SF by then, but who cares, a "mainstream" author wrote it now!

One good example: Fatherland by Robert Harris, published in 1992. The plot: The Axis Powers won World War II and we explore an alternate Earth in 1964, where Hitler is still alive, most of Europe is under German authority, the Autobahn goes all the way to Moscow, and no one talks about what happened to 11 million Jews who used to exist before WW2.

http://en.wikipedia.org/wiki/Fatherland_%28novel%29

An excellent story, to be sure, but alternate histories had been a long staple of SF by then.
But Fatherland was a "mainstream" novel, that's what made the difference with the so-called critics.

I do understand about SF fans being sensitive, but that doesn't mean we can't criticize poor SF or long-worn plot ideas when they come along, which is far more often than not. Otherwise we will keep getting the dreck from Hollywood and hack writers.

I can count on both hands the number of really good and really SF television series and films that have been made. The rest are mundane ideas dressed up in spacesuits.

I think SF is very important as a means of getting across very important ideas. That's why I am as critical as I am and will not hesitate to poke holes at plot contrivances and bad science.

I would like to see an SF series where none of the characters are human, nor do they look like humans with funny noses and ridges on their foreheads. There aren't just three networks any more, someone can afford to experiment and try for a little imagination-stretching.