It's not easy to change the public's perception about the genre, Conn. But at least SF/F books are getting more popular. Only when a reader gets into it, he/she will realize how many literary gems among it. There are craps in every genre, I just don't understand why some people who rarely read SF/F books look down on them as if they are 'low brow' read.
As for Kurt Vonnegut, some feel 'uncomfortable' to label his books as SF because despite the time/space travelling, aliens, spaceships in his books, his writing is, after all, all about earthlings and humanity.