As it happens, I like both hard sf and the kind where the author is obviously making it all up. I wish there was more hard sf, but I don't want the squodgey soft stuff to go away.

Van Vogt/Alastair Reynolds and Hal Clement/Greg Egan write very different sorts of sf.

I don't see how you can talk about science in sf without allowing for what was known at the time it was written. This isn't an arbitrary variable-- science fiction authors aren't clairvoyant.