On top of that because nobody has been doing any maintenance or monitoring of your server, nobody has noticed that one of the drives on your server has failed so there is no longer any redundancy and one more drive failure (which could happen at any moment) means EVERYTHING is gone.
I have just recently seen a company who shall remain nameless get infected with Cryptolocker. They felt confident that their backups would save them so went ahead and deleted all the encrypted files.