Susie Bright has posted an interview with author Sera Gamble that touches on why Real Dolls are creepy:

As for grown women with doll collections — while I didn’t look at them and think, “This woman is perverse,” I do have a reaction. I look at the dolls and wonder why this woman is collecting legions of fake babies. In the end, my response is a visceral one. Dolls are creepy because they so closely resemble real children — pretty, well-dressed, frozen children. Those “Real Dolls” creep me out because they look a little too much like a real woman. Specifically, a staring, motionless, dead woman.

I used to be in a kickboxing class that used a plastic dummy that looked like a man. We would practice aiming kicks at various body parts. Punching a dummy feels different than punching a bag. There’s a strange feeling that you’re almost doing something wrong. Like you’re beating someone up who has to just stand there defenseless. Like you’re doing violence with no accountability. Then came the day when someone put a clown wig and lipstick on the dummy. Now we were humiliating him, too! It was funny, but I felt like underneath, we were indulging some ever-so-slightly dark impulses. God only knows what we would have done to him if he was anatomically correct.