It may end up being there are multiple launchers: one that accepts a single passphrase, one with three-part login, one which expects bip39, one which requires a file containing encrypted credentials, one that uses sqrl etc... after all, this is just a way to derive an underlying secret.
I can see the maidsafe launcher will be 'the main launcher' and default for all new users, but it's not like it must be the only launcher.
A good option is to have a widget built into the launcher create-account process which can generate passwords in various formats and to various strengths to suit the user.
To me the biggest problem with login is brains can't generate randomness. It's up to the app to provide as much help generating a random password appropriate to that user both in format and in strength.