Good question, nailit. As a female I have often demanded an answer to this question myself. I think it is something to do with male hormones and 'we go to war, the women hold the hearth'. This is OK as far as it goes (women are the nurturers) but then comes the assumption that the male role is the superior one, which it obviously isn't - but men think it is. At that point we arrive at the physical argument - women are(mostly) not as strong as men and so physical bullying (or the fear of it) comes into play.
(I exempt my daughters - most men would be hard-pressed to equal them physically).
Decent men have nothing to be ashamed of. I adhere, happily and generally tolerantly, to Christianity, but one has to understand the mores of the time in which the gospels were written. Jesus was quite happy to honour women, just that the society he lived in had different ways of accepting them. I wish I were more of a theologian and had quotes at my fingertips. If you understand the 'flow' of Christianity it makes more sense, at least to me.
Certainly, the society I move in does not denigrate the female - more the reverse! :o) I can't answer for other religions, which seem to me to be horrific in their attitude to women.