I haven’t looked at all of the passages on this matter carefully, but i would be interested where the sexist portions are.
The text you quoted might simply mean that women and men ordained having close proximity are liable to fall to temptation, making Buddhism as an institution die out more quickly than if one of the sexes was not present, and hence more physical seclusion.
If you’ve ever read Ajahn Chah’s biography, he had already made arrangements to marry a girl, and it was because her parents didn’t think him a suitable candidate and voided the engagement that we were able to have the privilege of Ajahn Chah the forest monk. Ajahn Chah also talked about the temptations of sensuality and women when he was a young monk, and how it got better as he aged.
This is one of the great Masters we’re talking about. Imagine how all the non-masters are, if you have a bhikkhu and bhikkhunis living in close proximity? It seems very obvious to me that Buddhism as an institution would have a harder time surviving than if the sexes were completely separated. Nothing sexist about it, just defilements of lust affecting both male and female.