Ok, I get what you mean rlogin and rsh are not safe because of inumerous legacy problems. But I think you get what I meant as well, authorization problems can be solved without SSH.

I said that even rsh would do because will can ignore all the weird outdated stuff and just login with an user and password, same as a local login. In that case telnet would also work.

However, I truly believe that cryptographic keys are way superior to passwords. And going back to them would be a huge step back