Why is sexism still a socially acceptable ism?

Why is sexism still a socially acceptable ism?

Why is it that people can express sexist views and still be considered politically correct?

Why is it that commercials still portray women cleaning the toilets, vacuuming, and breaking up with their mops?

Why is it that when we see women heros on TV they always have short, tight skirts and low cleavage?
Why is it that we finally have 2 medical shows where the headline charcters are women and both are in the stereotyped role of nurse?

Why are all late night talk show hosts men?

Why are the vast majority of TV political pundits men?

Why is it still acceptable to refer to grown women as girls (as if we are still children who need guidance and protection)?

Why is it seen as acceptable that 50% of the population has only token representation on the US Supreme Court, Congress, and the US Senate.

Why is it socially acceptable to regard women as sex objects rather than whole human beings?

Why is it that society still assumes that there are intrinsic sex roles?

I know that there are alot more whys, but I think that the answer is connected with my last why. The continued acceptance of intrinsic gender roles allows all the other examples of sexism to be acceptable.