One reason women dressed more modestly in the past was fear of men's verbal reactions. No more. There are vast checks on his sexuality, none on hers.
We should either drop all sexual harassment laws (except those prohibiting threats -- "Sleep with me or you're fired") or apply them equally to women. If men create a sexually charged work environment when they talk sex, women do the same when they show sex. "Hostile work environment" -- a trial lawyer enrichment program created by feminist anger at men -- should be either dropped as a legal concept or applied equally to women's dress.
A fifth reason is the most obvious -- a desire to attract men.
Every woman knows that the quickest way to attract a man is to have him notice her. So it makes sense to assume that the more of her body she shows, the more men will be attracted to her. The problem with this approach is that unless all she wants is sex that night, provocative outfits are not usually in her best interest. Why not?
This leads to the sixth and final reason: women's naivete. It is doubtful that women have ever been as naive about men as are large numbers of contemporary educated women. I believe that my grandmother who never went to school understood men better than the average female college graduate today.
So, as a service to any woman who is confused by the difference between "cute" and provocative as regards women's clothing, this may help. What you often call cute or attractive, men see only as a sexual come-on. If you wish to dress for sex, you should be entirely free to do so. But if you want love and attention, you have to know the difference between dressing for sex and dressing to be cute and attractive. The more skin men see, the more they think sex, not love. And that includes guys your age, your male teachers, your clergyman, your mailman, and the old man next door.