Actually, I think this new UEFI Secure Boot could backfire everyone: the user who cannot install a different Operating System; Microsoft could have the same problem when the user wants to switch to another version of Windows; mainboard manufacturers if they have to provide a *simple* way of updating / managing certificates: and by *simple* I mean a very fool proof user interface, not the usual 80-chars-navigate-using-strange-keys BIOS interface they still produce.
I don't think that UEFI is a feature worth the cost.

Security problems are divided into two big categories:

1 - remote exploit
2 - local exploit

The hack a site using the first category, you have to find a bugged service (ie: ftp, http) running on the machine.
To hack a site using the second category, you first have to gain access to the machine, using a shell.

Actually, SSH is not a security treat. It is one of the most secure way to remotely access your machine.
I think that the hacker, once he had a shell access on the Mac, has used some local security flaw (ie. some buggy shell command) to gain root privileges and then hack the website.

Giving an SSH shell account to the hackers indeed helped a lot: local exploits are more commons and less "watched" by developers because you actually have to gain a local access first you can use them.

But believe me: SSH is secure: I have it running on all my servers and never had a problem with it.