I remember trying to date a woman in college, she would drop what appeared to me as incredible hints, but if I acted on them she would just ignore me.
We once had a 2 hour conversation about how she just could not find a mexican restaurant in town and would do /anything/ to eat at one. So I found one (willed it into existence) and then she simply wasn't interested.
Thing was, I dont really care about the rejection so much as, it was super easy for me to have relatively deep and interesting conversation with a total stranger. This wasn't even the first one, previous conversations about "Why are cities taking up valuable agricultural land" and "The best gifts to buy a woman are power tools" went down much the same way.
If people are convinced that the conversation to be rejected in cant even take place then I guess I understand concerns about the birthrate a little more.