Comment by GeekyBear

> As a general principle, as a user, I expect a file on one computer to be usable on another computer.

As a general rule, I expect a file on an encrypted disk to be unreadable for anyone who lacks the encryption key(s).

> if I need to obtain some other thing from the original computer to "unlock" that file, I should be able to do it.

You can export your passwords to a plain text CSV from the original computer.