If you do not value the information stored on your computer, data loss may not represent a significant issue. However, for the majority of users, the loss of their data is likely to have profound implications, such as financial loss, time and effort, and emotional distress. Typically, users who are casual about data protection have not yet experienced data loss.
I'm currently using 3 RAID5 controllers in each of several media systems. This is being done in an attempt to preempt future data loss. I store large amounts of scanned, video and audio historical data that can't re replaced so I want to make sure that the loss of a single drive or even two in one array will not mean the permanent loss of all data.