Dumbledore is not real, so he can't do anything of his own free will. Basically he is a character created by the author in the story. He can only be as he appears in the story. Author's comments about they're own stories, especially stories that have achieved reknown, may be flippant if not carefully considered each and every time. Rowling is so famous, I think she is fed up with Harry Potter. In other words, Rowling probably gets asked this question so many times, it would be convenient to just say Dumbledorf is gay rather than go into explanations of why Dumbledorf, being a sorcerer, does not have sex... (doesn't have time, runs the school, too busy working on magic, deals with secret incantations, sex has a propensity to zap energy, no hot witches around, etc...)
Now remember Dumbledorf is a sorcerer, and sorcerers do not concern themselves with sex in stories such as Harry Potter. This is a children's book. Yep, it's gonna cause a lot of disappointment to loyal customers. Talk about confusing a kid who, in their mind's eye see a grandfatherly old man taking care of business around the school and such....and present some "hidden" character background which does not appear anywhere in the books. If Dumbledorf is gay, there should be some indication of it through the character presentation in the book at some point.
Well anyway, the author's comments were not well thought out but that's life. I gotta agree with the conservative posters here. Someone brought up a point about an author being free to say what they want about their work. They are free to say what they want, but to be scholarly it has to be justified by and within the work at hand. Can't pull character attributes out of a hat.
Les