I agree with you, distrubing
I was a tomboy and didn't get as much into playing with dolls like some girls, but took care of the ones I had. I simply cannot imagine any of us mutilating our dolls.
To me, this is a sign of pathology, maybe not so much in boys, but certainly for girls. Even a small sampling of young girls who engage in such behavior I find disturbing. It does not seem normal at all to me.
I think we had a Toni doll phase where you could style their hair. I wouldn't even want to cut my doll's hair because, even as a child, I knew it couldn't grow back and would be irreversibly changed.