[horsawlarway]

Primary/Secondary implies a replacement relationship.

Master/servant implies different levels of authority and control.

Personally - I find the later much more compelling from a descriptive standpoint for this use of passwords.

Honestly, there are a ton of alternatives that I think make more sense - ex - Control password - Premier password - God password (although this probably violates some other policy...)

etc...

but primary is more familiar and and they probably liked the alliteration. Really - this just feels like marketing, though.

It's a reason to make people think & talk about Mozilla that's.... drumroll... once again not actually a compelling product or experience.