I think Hickboy and Not_Punny covered it. Some insecure guys really are clueless about females or relating to others. They have shallow suspicions of how the world works.
Anonymity on an internet forum gives the opportunity to ask women stuff they'd be too embarrassed to ask women they know.
I think it goes beyond simple insecurity and hints at a form of cyclical reinforcing of insecurity. Insecurity generally feeds upon itself, wherein the paralysis of fear creates anti-social behavior which eventually validates and amplifies the fear which led to the initial insecurity.
Confidence, similarly, works in the same manner. Confidence brings about success and social worth, which itself validates confident behavior.
Switching between the two, however, is difficult. Rational individuals recognize their long history of failure. Confident people recognize their long history of success. It isn't natural to rewrite all of your coping mechanisms to social situations at whim.
So what to do?
For the guy with the silly face and slight shyness, why not attempt to latch onto a woman's affidavit that she would value his sex in order to gain some confidence, and hope that the slight light at the end of the tunnel snowballs into a real personality change? If that's the case, success! If not, oh well, nothing lost. Still insecure.
If that's the case, I'm not sure what the proper response is. On one hand I'd like to help the guy find some modicum of happiness, but at the same time I really dislike lying. I do know, however, that if the actual source of the behavior is insecurity, then savaging the class of people that acts in that manner will only feed their need and will produce more twisted bullshit moving forward.