It seems you're onto why all the federation stuff is bunk...

Keep in mind that it's security model is no different than a large exchange, one who has diverse stakeholders (regulators, customers, management, shareholders etc) with a multisig vault.

Would anonymity of members give it an advantage over exchanges?

That assumes there would be users of an anonymized federation in the first place.

The concept of the federation is to trust a quorum of its members, so why would anyone choose a federation if you don't know who the members are?

This is why the software exists, so affinity scammers can issue debt tokens and pretend it's Bitcoin. Without the affinity, how would you scam people into using your mint?