Good questions changeling. I think in a way you've answered it at the same time. I'd say for many women it revolves a lot around social status and network of friends and unless something happens that shakes their world many would feel like they are betraying those left behind if they suddenly started doing something out of character. In my experience, for ladies its about what whole experience makes them feel like and at the center of it all are friends and family. It is only after their little world is safe that many tend to explore the evidence.
Men on the other hand tend to look for hard facts before they let feeling kick in, for a guy its way easier to say "to hell with this", pack up and leave, start over and never look back. It's really not only when it comes to religion, I'd say most men are like that in general with pretty much everything else.
It doesn't mean that either is superior way, they are just different. In life we need both details and bigger picture to make it complete. We equally despise heartless SOB who is only after the facts as well as someone who just melts all the time - this last is exaggeration to emphasize the point its not to say either side is completely like that ;)
I suppose that explains why when marriage is involved it becomes particularly difficult when say man realizes he's in a cult, and attempts to reason with his wife using facts and she accusing him of ruining everything, basically upsetting chemistry of harmony. Neither man will succeed using facts alone nor will wife succeed by playing on his feelings. So what tends to happen, for example, husband sticks around because of kids or because he still remembers what she "used to be like", hoping eventually "she would see the light" which will never happen unless she "feels the light" and vice verse. So if still in he in a way turns into a shadow of himself and she lives in her head hopping he will change. End result being, marriage either dissolves or they stay together where one is hoping the other will start "feeling differently about the truth" and the other "that other side will see the truth about the truth" Progress is made when they meet in the middle, if that happens at all.
Of course, this is just a rough analysis and you'd really need to have hard numbers to see if theory fits the data that may explain the disbalance in numbers. ;)
As for the board attendance, well guys do need some place where they can say their opinion openly so if marriage doesn't provide avenue I'm not surprised there's lots of married boys here. So when it comes to threads you can see guys tend to have hard factual discussion and girls tend to speak about social and humanistic issues, I say tend to, its a tendency not a golden rule. There are several highly schooled and intelligent, and factually oriented ladies that have been posting here for years, as well as there are guys who are more artistic in their expression.