In these haredi events where men & women are segregated is because it is because in Halacha women & men who are not married or family do not sit together that is their custom as they are orthodox Jews but as a result o hatred of the haredi and political correctness seculars think they have a right to dictate to the orthodox how they must do things.
Reality its not haredi trying to impose their ways on seculars its seculars trying to impose their ways on haredi.

As for mixed schools, I went to a non Jewish school in the UK which was for boys only so thats not just segregation in classrooms thats no girls allowed but there are lots of schools like this and people must be happy with it otherwise they would be demanding change

In Israel the problem is seculars hate the haredi which is why they make such a big thing about segregation and not serving in an army that doesn't need or even want to spend its limited budget on drafting them for political reasons.

to the parents fighting against gender segregation: will you oppress the rights of parents who want something different than you? some of us benefitted academically and socially from segregated education, being spared such things as sexual distractions, teenage rapes, etc. Will you force your agenda on the rest of us?