Backups are redundancy
out of firing range of problems like, say, hard drive meltdown, operator error, etc.
I've had gruntled employees, occasionally myself, run some variant of 'rm -rf' unintentionally far more often than I've had to deal with the other sort.
If you feel my grandparent post was advocating against backups, I'd strongly suggest you re-parse it. It's distinguishing between varieties of redundancy.
