Chestnut
I don't see a problem with voluntary organisations like the WI, Guides or Scouts being for one sex only. No-one has to join them and I can't understand why any of them have to be open to both sexes. A religious organisation has to be open to both sexes, but it's their decision how they wish to worship. If the women of that religion feel there is discrimination then it's up to them to protest.
I consider all forms of discrimination and segregation wrong, race, gender, colour. There are no exceptions. People have no choice about their race, gender or colour so it should never be used to choose how you interact with them.