Women were socially important in Egypt as far as the Ptolemaic dynasty, at least. It didn't fully adopt Byzantine culture until the 5th and 6th centuries CE, and this change was largely fostered by the collapse of the Western Roman Empire. So no, there was no "decline" due to their social system, only a largely unrelated cultural/memetic replacement. (It did fall to the Persians and then to the Arabs shortly thereafter, but by that time the ancient Pharaonic customs had been forgotten.)
Through LessWrong, I've discovered the no-reactionary movement. Servery says that there are some of you here.
I'm curious, what lead you to accept the basic premises of the movement? What is the story of your personal "conversion"? Was there some particular insight or information that was important in convincing you? Was it something that just "clicked" for you or that you had always felt in a vague way? Were any of you "raised in it"?
Feel free to forward my questions to others or direct me towards a better forum for asking this.
I hope that this is in no way demeaning or insulting. I'm genuinely curious and my questioning is value free. If you point me towards compelling evidence of the neo-reactionary premise, I'll update on it.