Traditional practices and attitudes are a sacred category in this sort of discourse, but that doesn't mean they're unassailable -- it just means that any sufficiently inconvenient ones get dismissed as outliers or distortions or fabrications rather than being attacked directly.

That works a lot less well arguing against someone who is claiming to be from that culture.

It helps, of course, that in this case they'd actually be fabrications.

So? Most of the "traditional practices" SJ types sanctify are fabrications. That doesn't stop them from sanctifying them.