Ursula K. Le Guin said this quote

...[T]he only means I have to stop ignorant snobs from behaving towards genre fiction with snobbish ignorance is to not reinforce their ignorance and snobbery by lying and saying that when I write SF it isn't SF, but to tell them more or less patiently for forty or fifty years that they are wrong to exclude SF and fantasy from literature, and proving my arguments by writing well.