Female adjective re job title

Why is it common to hear "women writers" or "woman doctor" but not "man author"? Isn't an adjective required in both cases, thus "female guitarist" and "male accountant"? I am asking about why the noun woman is used instead of the adjective female and why this error seems to be made only in relation to women, not men. This is not a question about the appropriateness of such qualifiers.

Solution 1:

You do hear 'male writer' and 'male musicians' only much less often.

This is unfortunately due to most professions being dominated by men leading to women being treated unfairly which will in turn raise a debate. Men are the norm in these professions so there isn't usually a specific detail to discuss (which is why you don't 'hear' it)

You also hear it more often with ethnic minorities for example in the UK 'Black police officers'

This is for many reasons such as there being less black police officers than there should be which raises a debate, and in turn you hear it.

To be honest this is more a question of society than language, but I hope my answer makes sense :)