The ftp-remote-edit extension stores encrypted connection information. Other extensions are more conventional in allowing a per-session password input. Remote FTP, for example. The ability to use that package for SFTP access is therefore desirable.
If you don’t want Atom to handle any sensitive info then just use the SSH Agent login type. You’ll still need to set a password, but that doesn’t seem too much of a hassle.
It would probably also be possible to add the capability for per-session logins to ftp-remote-edit. Switching Juno to ftp-remote is not going to happen since that package seems abandoned.