It's a matter of respect.

Why shouldn't women, teens, and girls dress in a sexy manner? It's because we live in a culture of disrespect and sexual malfunction. Sexuality and pleasure are still seen as dirty, evil, obscene, and immoral.
I saw a recent meme where certain actresses were shown dressed showing allot of cleavage. The point of the meme is that these women were inviting assault. As a man, I can enjoy the view without having to assault or harrass any female. I wish I could just say "thank you!".