I have raced with the SCCA since 1993 and they have separate classes for ladies and for 10 years I have owned a kart track and 10% of our drivers are female, so I have a lot of experience with women in racing. You can disagree with me all you want but I can back it up with strong evidence. I'll try to make this short but it's complicated so I have to skip a lot. Some background on basic human development will help explain this. Basically, for at least 100,000 years, humans have separated the tasks of men and women. When there was a rustling in the bushes, the men have grabbed their spears and gone out to kill whatever was out there, and women have gathered up the children and hid them away for safety. These are two very different impulses when faced with danger but the divided tasks have allowed us to survive. Put simply, a male who didn't go out and kill for food or defense probably didn't have his genetics carried on, and any woman who had the urge to go out and kill for food or defense probably didn't have her genetics carried on, either.
Fast forward to today and we are told that men and women are the same and that simply isn't true, equal yes, but not the same. Men deal with a rush of adrenalin much different than women. Men rarely freeze up when confronted with a dangerous situation and I have watched hundreds of crashes at my track and men will always keep steering and stabbing at the pedals right to the bitter end, where women often are frozen at the controls and take their hands off the wheels and even cover their eyes. Staff joke that men crash because they refuse to use the brakes and women crash because they can't find the brakes. Men almost always start off foot to the floor and only back off once a crash is imminent, women almost always start off slow and get faster as their confidence builds. And this trend is exactly the same with the local karting club.
I am not saying that a woman cannot drive as well or better than a man, just that women in general are not as adept at dealing with everything going on inside a race car. I compare it to tall players vs short players in the National Basketball League. You don't have to be be 7' tall to be a great player in the NBA, but it helps. Being only 6' tall doesn't doom you to failure, either and the league has had some very successful players under 6' tall, they just have to work a little bit harder at it. A woman has to work just a bit harder than a man to be a great driver because the whole thrill seeking/adrenalin rush thing is not something that comes natural to most of them. I cheer most for Danica in NASCAR and I really want to see Susie have a shot at F1 because in many ways they have struggles the men don't have and I like underdogs.
What does my wife think about my opinions on this? She agrees completely because she also works at the track, has seen all that I have seen and she is an SCCA National Champion in the ladies class. In case you're curious, women make up 10% of our customers but represent 45% of our crashes and in 10 years, only 3 women have had the top lap time of the day (and two of those were students in my kart racing school, one was 12, the other was 50, the third female is the driver of the local FSAE car). And women should have an advantage in my karts, their average weight is lower than mens. Women showing up at our race events get more than their fair share of assistance, too and the local sports car club puts on a ladies only driving clinic every year. Anyways, I want females to be given a chance and I believe they add to the show, plus sponsors love the attractive ones, as do most of the fans. Believe it or not, this was the short version.