Science Fiction or not Science Fiction?

Didn't post yesterday - rushing around too much!  Still, did some great writing and got together with a good writer friend to chew the fat. 
My friend and I consider ourselves to be Science Fiction writers.  We generally think the SF genre needs to broaden its horizons; it seems to be a very narrow market at the moment.  Most of the SF books that are on sale are very similar and very blokey in appeal! The other thing is they are so often lumped together with Fantasy which narrows them down even more.

Our SF books are not about weird alien monsters and battles in the stars; not that there is anything wrong with that, it's obviously very popular.  We believe there is a market for SF books which are more to do with unusual circumstances effecting every day life and normal people.  There were once many books in this vein; 'Day of the Triffids' by John Wyndham is a prime example and my favorite book of all time.  It is not really about huge man eating plants but the struggle ordinary people have to deal with how their world is destroyed by them.  It is also a love story with Bill searching the Triffid infested countryside for his soul mate Jo after they have been separated in London.  This book has been hugely influential in my work (my main protagonist is even named after Jo and has some of her qualities). 

Take a more recent book; 'The Time Traveller's Wife' by Audrey Niffenegger.  This is a great read about a man who travels back and forth unwillingly to different times in his life and how this effects him and his partner.  It's about the strength of their relationship in having to deal with his rather odd personality trait.  To me it's a SF book yet it's found in General Fiction.
If the publishers and agents of SF were to open their doors a little wider and take on some different styles I think they would find a huge untapped market out there.
Also I might get my book published!