why use them at that price...hard drives are so much cheaper, etc. I have 6. I may never use optical media again!!!!
It's true, hard drives are certainly cheaper than Blu-Ray media, and I can see why the convenience hard drives would be appealing.
However, they have a few big disadvantages when it comes to storing important data. First, they have moving parts, which makes them prone to sudden failure with few to no warning signs. Even if they're not in use, the motor will eventually seize from lack of use. Quality CD-R, DVDR, or Blu-ray media should suffer from these problems. Even if a certain batch were to be prone to early failure, it would likely be possible to detect problems before the disc becomes unreadable.
Now of course, something like a RAID 5 array would probably offer even better reliability than recordable media, but those are pretty damn expensive.