It's like a blog written by a 22 year old straight out of college that's never dealt with a real production deployment/failure
Zfs on Linux has data loss bugs. There's at least one unpatched and there are bound to be more.
Single huge servers eventually fail. Maybe it'll be a drive controller. Maybe it'll be CPU or ram with bit flips as a side effect. Downtime would be the least painful part of the eventual failure.