Is Sci Fi Gay Friendly?

The LATimes carried a story Friday suggesting that most Star Trek fans accepted Sulu's coming out "with the respect for diversity that devotees say is the hallmark of the sci-fi series." I myself question whether science fiction, as a genre, is actually that open-minded. Considering the premise of most sci-fi is to project possible human futures, the virtual invisibility of homosexual characters, let alone couples, is striking. (Probably has something to do with the fact that its target audience -- young males -- is actually quite conservative.) Makes me wonder if authors imagine gayness is something that will someday be cured.