views on twerking

Why is twerking viewed so negatively? Especially around children or if you're a mother. It's literally moving your butt in a circle. It's dancing, you're moving with the rhythm of the music with your body. It's dancing. I understand some people view it as sexual, but have you seen some salsa dancing or dances similar. They're very sexual, but no one batts an eye if a mother was seen salsa dancing. Someone care to explain?