So you would say "The Caves of Steel", "The men in the high Castle", "Flowers For Algernon", "The Right Hand of Darkness" and "Star Trek" are part of the same genre? I can't really agree with that, I can't not call any of those Science Fiction.
I consider that 'literary' science fiction, just as I do the earlier mentioned Cryptonomicon, even though there were no futuristic technologies in it.