True, but that's not a gender issue per se. Women-only programming groups are based on the theory that women are not being well served by co-ed programming groups, as a combination of socially enforced gender roles plus an understandable discomfort at being the only woman in a room. All male groups are generally frowned upon because there's no reason to think the average male would be prevented from participating in a technically co-ed but heavily male group.

I suspect men-only clubs for traditionally female dominated fields, something like an all male kindergarten teacher group, would be broadly accepted as reasonable.

Since you can't really eliminate backroom dealing, male only social clubs can have the practical effect of excluding women from equal participation/opportunity, at least as long as groups like "C level exec" are disproportionately male.