For me, I like yaoi for the same reasons I like "normal" pairings. (Really, what is normal? I think love knows no gender. So yeah. I don't care either way. But I'm still straight. Love teh guys.)
I have to like a pairing based on the people and the chemistry. I personally like shonen ai and more of the mushy drama stuff than i like the graphic yaoi stuff. But I like em both.
Basically, the gender of the people in love in the story have no affect on me. So yeah. There's my story.