The title of this post is a great question and answer about women and how women are perceived. It comes from an image posted on Facebook and I love it! No one ever asks a writer why they write strong male characters, so why ask "why" about strong female characters? Women aren't strong enough?
Quite honestly, the strongest people I know are women, not to say that men aren't but men generally aren't expected to do everything the way women are. Women are supposed to take care of the family (a seriously underrated activity - a 24/7 job) plus work outside the home and still keep it together to make everyone else happy. I have yet to hear a man speak of striving for a "work-life balance" because men aren't normally expected to shoulder the world. Women need the work-life balance because everything is skewed against them.
Yes, feminism has brought us a long way and not all in the right direction but the basic sense of women as... less still persists. Women are the foundation upon which society depends upon for its very survival - that may sound dramatic, but it's not. Without the bazillion hours of unpaid largely female labour in the home for the family, society would fall apart. In fact, if stay at home mothers were paid, it would be an $80,000 per year job. Not too shabby. But because "women's" work is unpaid and unrecognized, it doesn't count. This is what society tells us. Society tells us to always put others first in subtle and not-so-subtle ways. Be NICE and QUIET. Don't make waves, cooperate. An assertive man is strong but an assertive woman is a bitch. An unnatural creature. And the saying for a woman to be considered half as good as a man she has to be twice as good is true. People take women less seriously. Always have. Hopefully this will change.
And so it comes down to writing these 'new' stereotypes - showing women as they are: strong, capable and tough - I say go for it. I've read a lot of women's and romantic fiction and some of it drives me crazy. The brooding hero, who is damaged and self-loathing and hurts everyone around him because he's a miserable SOB, is a particular pet peeve. Why would any woman EVER love this guy and then lay down for him to wipe his feet on? That's not a heroine - that's a door mat who's even more damaged than the guy. I want a hero who has his shit together because I don't want to be picking up his crap. And I hate to see the "heroine" pick it up.
I generally stop reading at that part because then I want to slap sense into the heroine AND hero. I'm not sure who I'd hit harder because they both piss me off. And I WISH that writers would stop writing characters like these - they aren't helping anyone see themselves as strong. I mean, yes, I write screwed up characters but they're strong screwed up characters - there's a difference. lol :D
Joss Whedon is a wise man ahead of his time.