It is just sexist jargon that has entrenched itself into the realm of acting, and to be honest with you, It will not be leaving any time soon.
However, people usually use the word in a unisex context when speaking. For Example:
The actor Denzel Washington appeared in Out of Time, with the actress Sanna Lathan (Typo On Name).
However when used in a plural form, the noun looses gender:
The actors in Out of Time were a great cast.
It just some good ole english, nothing too worry about. But I do understand your point.