RAID is something that can supported at the hardware level (hardware RAID) whereas ZFS requires software support. Also, some businesses use Windows Server. Are they wrong for not using ZFS?
If you read the Linux developer's article that this whole thread is about, you will see reasons you should not use hardware RAID for some years now.
And yes, most people should default to ZFS for everything on FreeBSD/IllumOS/Solaris/Linux. There are specific cases where you should use XFS or UFS on these operating systems such as fail in place and overlay filesystems (HDFS, Ceph, Swift etc) but times have changed, the tables have turned, these non-ZFS filesystems are now expert territory with here be dragons warning label.
