I have a small business and the thought of hard drives failing, whilst an inconvenience, doesn't worry me too much as I know that all my data is backed up in at least two places.
If a hard drive did fail, I could have the machine up and running again (possibly better than before) within an hour by replacing the drive and loading the data from the backup on to it. I know this is possible because I've recently done it.
All computers that contain data of the least importance should be backed up - it is folly for them not to be. To have a business computer not backed up is unwise to say the least and the word stupid comes to mind.