[Neco]

Sorry for the necro. I just want to reply on this.

It is MORE SECURE than a complex passwords. It would take years to crack those private keys. Who would want to brute force a 2048bit key?
Passwords are less secure and can easily be bruteforced. No one would dare bruteforce a 2048bit key unless you're a very important person.

It is better to use ssh keys instead, or really complex password. When I use passwords I usually create them using some generator so it would be strong enough.