Calling the guys who hacked you "script kids" and "idiots" is just childish. You failed to take basic security measures and got fucked over by people who know better than you. The bigger idiot here is the one who was hacked.
Anyway, I have already mentioned in my post that I was an idiot to forget about the installation. Sure, and that is what I have learned about: not to forget again.
That said, hacking is non acceptable no matter what mistakes the owner of a website has done. I really have no respect for such people.