Bill O'Reilly is right. For the wrong reason, of course. And he thinks it's a bad thing. I think it's a good thing. Brokeback Mountain's popularity in Middle America is humanizing "gays", the lurid construct that persists in so many minds, and thanks to Bill for pointing it out.
Of course, our many friends who are gay are plenty human enough, and don't need to be humanized, as so many have pointed out. Well, perhaps some do, as do some straight people, but that's a different matter.
What the movie does is to humanize "gays"; here I'm using the quotes to distinguish the reality from the construct, as Mark Crispin Miller does to distinguish "Clinton" from Clinton. Now the movie's audiences are shown that the construct is false, with homosexual love separated from the popular image of the paedophile transvestite queen, and the icky thought of men sticking their...you know...in each other's...you know. They can understand it's about love. Women in particular are said to be struck by the movie. It usually begins with the women.
Like Bill said, Brokeback Mountain is putting human form on the false diabolic image, "gays", that he and his friends have popularized, and it's time.