I don't care if a company has triple redundancy. I backup my stuff, because I don't want to lose it. It's MY data after all. Simple as that.

RAID is not for backup, btw. RAID is for speed and/or redundancy. Having a RAID 5 system does not absolve the operator from backing up their data. The chances of complete data loss are minimized, but still can happen!

Backups are the most important thing about using a computer. If you don't value your data enough by not backing it up, how are you to complain about losing them?

Edit: You spend maybe thousands on a new computer, but you don't want to spend 50 bucks for a cheap, external hard drive to do a backup on?