It's certainly very odd as men are attracted to the sex while women are attracted to having the kid - and Mother Nature intended for both to be logically correlated. Looking back I did have one girlfriend who always said that she didn't want kids - I think mainly because of the pregnancy sickness and morbidity; she was not so much a caring person, but she was very sexually receptive. I had another girlfriend who said that she only wanted 1 kid; perhaps it was for a similar reason, and her being an only child, she liked the idea of the attention. OTOH, I had a girlfriend who was the last of 14, and she said she wanted a big family (but not quite that big). In fact, now that I think about it, most or all girlfriends I've been with have let it be known how many kids they wanted. I have usually responded that 2 plus the last one (i.e., you never know how many you'll actually get per brood) sounds like a responsible number.
As for myself, as I see myself as being very uninvolved during the diaper & vomiting phase, I don't feel like I have room to really demand anything.