Supernatural and female representation

This article sums it up pretty good: Why fans are upset about the supernatural nerd HQ

The answer 'We don't need more woman in Supernatural because we don't need romance' exactly proves a point I tried to make in an argument a few weeks ago.
We need more women in tv shows, movies, etc., because whenever there's a female character, you know exactly there's a reason why she is there. And the reason is almost ALWAYS in connection with her gender. Most of the times the reason is one of the following things: a. she's a love interest. b. she's a motherly figure to the male character, or c. she gets fridged to motivate the male character.
(Charlie is an exception to this rule and I really love supernatural for this character  )
I want to see more woman in tvshows, just because they're fucking human beings who make up 50% of the population and have lifes and jobs! Where are the female police officers, the doctors, hunters, etc.? If it doesn't matter at all which gender a character is, why is he most of the times male? Doesn't make sense to me at all...