"With optical media the reading mechanism is separate from the media the data is stored on which means if part of the reading mechanism fails the disc can easily be removed"
isn't that part of the problem with optical media? Every trip from storage to the reader is an opportunity for damage to occur. At least a hard drive's disk is kept safely in a metal box away from humans.
Q: How many IBM CPU's does it take to execute a job? A: Four; three to hold it down, and one to rip its head off.