Why were women banned from the stage in Shakespeare's time?

In Shakespeare's time ACTING WAS NOT CONSIDERED APPROPRIATE FOR WOMEN.

"England was the last of the European countries to accept women on the stage. In the year 1629 a visiting company of French players gave performances at Blackfriars, with actresses."

Women were considered to be the property of men, first their fathers, then their husbands.  It was not appropriate for a respectable woman to be alone with men without a chaperone from her family.  Women did not work outside the home, unless they were very poor and cleaned or worked in the kitchen for another family.  Many respectable women did not even attend the performances of plays because the environment was so rough and vulgar.  Actors were considered vagabonds and could not be trusted. 

"English writer of the time called these women "monsters"; and the audience would have none of them. They were hissed and "pippin-pelted" from the stage. Boy actors were immensely popular, and the schools were actually the training ground for many well known comedians and tragedians."

For women, acting was on the same scale as prostitution in the 17th century.  Audiences would not have approved of seeing women on the stage, particularly in any love scenes. The whole company of actors would be rejected by audiences because the society would not be accepting of women on the stage.

"The stigma of dishonor rested, however, upon the whole profession, playwrights, players, and on the theater itself."