As a kid who grew up a tom boy, I was always bummed when I couldn't play the same sports as my male counterparts. It made me work harder and eventually I was the only girl on the team. I was even more bummed to find out as a 9 or 10 yr old that if I wanted to be in the military I couldn't "fight" (I started training in martial arts when I was 6, and thought I'd be a great soldier back then...).
The only disadvantage I may have as a fighter is my height, but I am not even average sized. There are just things that being just about 5'1'' won't let me do, but there are women out there who are as tall as men that could do all the same tasks. That being said, the only reason my height has ever been a disadvantage is when I used to sport fight. When there are no rules to how and what you can do in a fight, the size is much less of a factor. I use it to my advantage, I can fit places most average sized men can't, and really no one expects the 5'1'' girl to have tricks up her sleeve.
As for the change coming now, maybe its because women's athletics are being publicized and televised more now and hold much more ground than in the past. The US women's soccer team has accomplished a great deal and they're starting to get the recognition they deserve instead of just parodies of people tearing off their shirts with black sports bra underneath. UFC is helping show the world that women are just as capable fighters as men. There's even Danica Patrick out there turning left the the other boys. Maybe some of the menfolk out there that may have thought that women were physically inferior, are seeing this athleticism realize a female can be just as competent as a man on a battlefield.