There are certain threat/risk models where having multiple profiles might be helpful (non-forensic examination by an offical at a securtiy screening kinda scenario). But you're right, it's nuanced, requires know-how by the user, and possibly a foot-gun for some caught unawares. NOT an easy problem to solve. Personally, as a user, I'd like the ability to be able to choose that option in the instances where I needed it, but it's likey a TON of work for a very small actual user community who needs it.