It's pretty simple. If people want to treat women as completely equal to men, that's fine, as long as they post competitive times and qualify, I'd be happy with women in the tour. Same with baseketball, football, baseball, if a woman can be competitive, then it's just fair that they let her play.
However, biologically, while a woman can physiologically approach 98% of what a male can, it's that last 2% that takes an extra 200% more effort.
Someone correct me if I'm wrong, but isn't that why the olympic 100 meter sprints are separated by male and female?

BTW, there is a female driver in indy racing and she even lead a bunch of laps and had a real good chance of winning.