Stored passwords are perhaps the one thing you really need flushed from a system if you have security/privacy concerns. Private browsing doesn't store any of the session contents once you leave a private browsing session. It flushes, cache, cookies, , history, etc. for security. This includes any passwords used/saved during the session.

I agree that password protection may be considered important by some for Private Browsing, however if that is the intention, then it would be one of the delineated items such as...remember browser history, remember download history, etc. that are check-listed under that function. Also, having a separate Passwords option implies that their functions are mutually exclusive and therefore should function independent of one another.

Thanks for your response.