I don't "prefer" either. I have two boys, I love my boys. They're sweet, loving, caring, goofy, curious and so outgoing. They're a bundle of fun, and the joys of my life! I'm pregnant with my third child, and I am in this forum because I desperately want to add a daughter to our family.
It's a pretty simple concept, I just want the experience of dresses, and hair bows... A little girl to go and get our hair done together, or nails perhaps. My mother and I are best friends, I've always had such a great relationship with my mom (my dad too!!) and even though I expect to have the same relationship with my boys, I want to talk girly things with a daughter!! Boys tend to be more private with their feelings and experiences, and girls tend to share and keep you involved. It's not a 100% foolproof thing. It's just the ideas I have in my head.
I want to experience the other side of parenting a little girl. My eldest son is also desperately expecting a sister. I want to shop on the other side of the store... I want to learn how to do her hair... I have toys I have kept from my childhood, very girly toys, that I would like to give to her...
My attitude towards "gender disappointment" and wanting one gender over another is, I get it. I'm there. It's not something you can understand unless you have felt it. Just like so many other things in life. Everyone has their own varying degree of gender disappointment. Mine is a deep deep desperate desire for a daughter. But I would never ever regret having another child that turned out to be a boy, I've never wished either of my son's were girls. If this child is a boy, it will be okay. I will just be sad I won't ever get the daughter I so desperately wanted. It's a real, painful feeling for so many people. And people shouldn't be treated like criminals for feeling the desire for one gender over another.
Ultimately, the majority of people let it go, move and on and realize that child is perfect for their family.