I think the issue for some people (mostly men) is that they see women as being there for their viewing pleasure only. It's OK for men to get old because that's natural and they get to see a positive future for themselves. But a woman in a movie needs to look attractive - for them. It never occurs to those people that the woman may not be appearing just for their personal pleasure.
I agree. This is why womens careers tend to come to a halt when they turn 40. Or if your lucky you get to be the mom of the main character or something like that.
Jason