The following is a combination (and decompression) of several tweets1 promoted by a current brouhaha about gender segregation.
In general, separation (and segregation) of the sexes is seen as a means towards an end and not an end in itself. Unfortunately, people tend to see it as a totally inflexible end in itself, while fiqh sees it as flexible within limits.
The default is that men and women who are strangers do not interact unless there is a valid excuse for doing so. Valid excuses in the old texts include trade, medical need, testimony, identification and education. Contemporary fatawa address current issues, including conversing with colleagues, group projects, and today’s public sphere. Some Muslim societies restrict the flexibility out of fear that in their society it will lead to the unlawful. It is a mistake to take a highly contextualized application of law from its original context and inject it elsewhere.
So this isn’t an east vs. west thing; it’s a question of contextually appropriate means towards an end.
From what I read of the event,2 attendees could choose where to sit: mixed gender, men only, women only. Some attendees decided to make a point of taking away that choice from Muslim women who chose to sit apart from men. In another context people would be talking about denial of choice and consent—and harassment. But here people see only segregation and completely disregard female Muslims making their own decisions. It is ironic that concern for female Muslims having a voice in the future denies them having one in the present.